Servers Playground How we check Add a server Log in

TapTax

Working · 1.8 s

uk.co.taptax/taptaxv1.1.1 Domain verified

UK tax: take-home pay, self-employed and company tax, VAT, stamp duty, invoices and MTD.

Finance & Payments

Source Website Registry entry

Maintain this server? Claim it

Try it

Call this server's tools from your browser. Nothing to install.

https://api.taptax.co.uk/mcp

Requests go through mcptry because browsers can't call most MCP servers directly. Header values are sent to the server for that request only and are never stored or logged.

Tool list from our last check. Connect live to refresh it.

add_transaction

Record a business income or expense in the signed-in person's TapTax, such as a receipt or a payment. The category is the HMRC self-employment box it belongs in. The same entry added twice within 10 minutes is recorded once.

datestring, required

The date on the receipt or of the payment

typestring, required

amountnumber, required

In pounds, VAT included

categorystring, required

For an expense, its HMRC self-employment box (SA103F): costOfGoods: materials, parts and stock used in the work or sold on, e.g. trade and building suppliers such as Screwfix, Toolstation, City Electrical Factors, Edmundson Electrical, Travis Perkins, Wickes; constructionIndustryScheme: payments to subcontractors under the Construction Industry Scheme; staffCosts: wages, salaries and pension contributions for employees, and payments to non-CIS subcontractors; travelCosts: car, van and travel: fuel, vehicle insurance, servicing and repairs, road tax, parking, tolls, public transport and taxi fares, and hotels and meals on overnight business trips; premisesRunningCosts: rent, business rates, power, heating, water, insurance and security for business premises (never vehicles); maintenanceCosts: repairs and maintenance of business premises, machinery and equipment; adminCosts: phone, broadband, postage, stationery, printing, small office items, and software and app subscriptions such as accounting or tax software (TapTax, Xero, QuickBooks); advertisingCosts: advertising, marketing and website costs; businessEntertainmentCosts: entertaining clients or customers; interest: interest on business loans and overdrafts; financialCharges: bank, overdraft, card and payment-processing charges; badDebt: money owed to the business that will not be paid and was counted as income; professionalFees: accountants, solicitors and other professional fees, and professional indemnity insurance; depreciation: depreciation of equipment (rare in a bank transaction); other: other allowable business costs, e.g. protective clothing, trade and professional body memberships, public liability insurance. For income: turnover (sales and fees) or other (other business income).

descriptionstring, required

Supplier or client, and what it was for

personalboolean

True for a personal (non-business) payment

This tool isn't marked read-only, so it may change something on the server or in an account you connected.

I understand, run it anyway

TapTax MCP server | mcptry

TapTax

Working · 1.8 s

uk.co.taptax/taptaxv1.1.1 Domain verified

UK tax: take-home pay, self-employed and company tax, VAT, stamp duty, invoices and MTD.

Finance & Payments

Source Website Registry entry

Maintain this server? Claim it

Try it

Call this server's tools from your browser. Nothing to install.

https://api.taptax.co.uk/mcp

Requests go through mcptry because browsers can't call most MCP servers directly. Header values are sent to the server for that request only and are never stored or logged.

Tool list from our last check. Connect live to refresh it.

add_transaction

datestring, required

The date on the receipt or of the payment

typestring, required

amountnumber, required

In pounds, VAT included

categorystring, required

descriptionstring, required

Supplier or client, and what it was for

personalboolean

True for a personal (non-business) payment

This tool isn't marked read-only, so it may change something on the server or in an account you connected.

I understand, run it anyway

Tools (49)

add_transaction

Argument	Type	Description
date*	string	The date on the receipt or of the payment
type*	string
amount*	number	In pounds, VAT included
category*	string	For an expense, its HMRC self-employment box (SA103F): costOfGoods: materials, parts and stock used in the work or sold on, e.g. trade and building suppliers such as Screwfix, Toolstation, City Electrical Factors, Edmundson Electrical, Travis Perkins, Wickes; constructionIndustryScheme: payments to subcontractors under the Construction Industry Scheme; staffCosts: wages, salaries and pension contributions for employees, and payments to non-CIS subcontractors; travelCosts: car, van and travel: fuel, vehicle insurance, servicing and repairs, road tax, parking, tolls, public transport and taxi fares, and hotels and meals on overnight business trips; premisesRunningCosts: rent, business rates, power, heating, water, insurance and security for business premises (never vehicles); maintenanceCosts: repairs and maintenance of business premises, machinery and equipment; adminCosts: phone, broadband, postage, stationery, printing, small office items, and software and app subscriptions such as accounting or tax software (TapTax, Xero, QuickBooks); advertisingCosts: advertising, marketing and website costs; businessEntertainmentCosts: entertaining clients or customers; interest: interest on business loans and overdrafts; financialCharges: bank, overdraft, card and payment-processing charges; badDebt: money owed to the business that will not be paid and was counted as income; professionalFees: accountants, solicitors and other professional fees, and professional indemnity insurance; depreciation: depreciation of equipment (rare in a bank transaction); other: other allowable business costs, e.g. protective clothing, trade and professional body memberships, public liability insurance. For income: turnover (sales and fees) or other (other business income).
personal	boolean	True for a personal (non-business) payment
description*	string	Supplier or client, and what it was for

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "type",
    "amount",
    "date",
    "description",
    "category"
  ],
  "properties": {
    "date": {
      "type": "string",
      "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
      "description": "The date on the receipt or of the payment"
    },
    "type": {
      "enum": [
        "income",
        "expense"
      ],
      "type": "string"
    },
    "amount": {
      "type": "number",
      "maximum": 10000000,
      "description": "In pounds, VAT included",
      "exclusiveMinimum": 0
    },
    "category": {
      "enum": [
        "costOfGoods",
        "constructionIndustryScheme",
        "staffCosts",
        "travelCosts",
        "premisesRunningCosts",
        "maintenanceCosts",
        "adminCosts",
        "advertisingCosts",
        "businessEntertainmentCosts",
        "interest",
        "financialCharges",
        "badDebt",
        "professionalFees",
        "depreciation",
        "other",
        "turnover"
      ],
      "type": "string",
      "description": "For an expense, its HMRC self-employment box (SA103F): costOfGoods: materials, parts and stock used in the work or sold on, e.g. trade and building suppliers such as Screwfix, Toolstation, City Electrical Factors, Edmundson Electrical, Travis Perkins, Wickes; constructionIndustryScheme: payments to subcontractors under the Construction Industry Scheme; staffCosts: wages, salaries and pension contributions for employees, and payments to non-CIS subcontractors; travelCosts: car, van and travel: fuel, vehicle insurance, servicing and repairs, road tax, parking, tolls, public transport and taxi fares, and hotels and meals on overnight business trips; premisesRunningCosts: rent, business rates, power, heating, water, insurance and security for business premises (never vehicles); maintenanceCosts: repairs and maintenance of business premises, machinery and equipment; adminCosts: phone, broadband, postage, stationery, printing, small office items, and software and app subscriptions such as accounting or tax software (TapTax, Xero, QuickBooks); advertisingCosts: advertising, marketing and website costs; businessEntertainmentCosts: entertaining clients or customers; interest: interest on business loans and overdrafts; financialCharges: bank, overdraft, card and payment-processing charges; badDebt: money owed to the business that will not be paid and was counted as income; professionalFees: accountants, solicitors and other professional fees, and professional indemnity insurance; depreciation: depreciation of equipment (rare in a bank transaction); other: other allowable business costs, e.g. protective clothing, trade and professional body memberships, public liability insurance. For income: turnover (sales and fees) or other (other business income)."
    },
    "personal": {
      "type": "boolean",
      "default": false,
      "description": "True for a personal (non-business) payment"
    },
    "description": {
      "type": "string",
      "maxLength": 500,
      "minLength": 1,
      "description": "Supplier or client, and what it was for"
    }
  }
}

calculate_capital_gains_tax

Calculate UK Capital Gains Tax on selling an asset (residential property, shares, a business qualifying for Business Asset Disposal Relief, or other assets) for a tax year: the gain after costs, losses and the annual exempt amount, tax at each rate given other income, and the payment deadline.

read-only

Argument	Type	Description
losses	number	Capital losses to offset
taxYear	string	UK tax year, e.g. "2026-27". Defaults to the current one.
proceeds*	number	Sale proceeds
assetType*	string	badr: Business Asset Disposal Relief
costBasis*	number	What the asset cost
otherIncome	number	Taxable income in the year, which sets the rate
disposalDate	string	Disposal date; only matters in 2024-25, when rates changed on 30 October 2024
allowableCosts	number	Costs of buying, improving and selling

calculate_child_benefit_charge

Calculate the High Income Child Benefit Charge on an adjusted net income and the Child Benefit received in a tax year: the charge, the benefit kept, and the income the charge starts from.

read-only

Argument	Type	Description
taxYear	string	UK tax year, e.g. "2026-27". Defaults to the current one.
adjustedNetIncome*	number	The higher earner's adjusted net income for the year
annualChildBenefit*	number	Child Benefit received in the year

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "adjustedNetIncome",
    "annualChildBenefit"
  ],
  "properties": {
    "taxYear": {
      "enum": [
        "2026-27",
        "2025-26",
        "2024-25"
      ],
      "type": "string",
      "description": "UK tax year, e.g. \"2026-27\". Defaults to the current one."
    },
    "adjustedNetIncome": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "The higher earner's adjusted net income for the year"
    },
    "annualChildBenefit": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Child Benefit received in the year"
    }
  }
}

calculate_cis_deduction

Calculate the Construction Industry Scheme deduction on a payment (labour only, materials excluded) at the registered, unregistered or gross-payment rate, the amount received, and whether the year's deductions are likely to be more or less than the tax actually due.

read-only

Argument	Type	Description
taxYear	string	UK tax year, e.g. "2026-27". Defaults to the current one.
expenses	number	Expected business expenses for the year
cisStatus*	string	registered (20%), unregistered (30%) or gross payment status (0%)
annualIncome	number	Expected self-employed income for the year
grossPayment*	number	The payment before deduction
materialsAmount	number	Part of the payment that is materials

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "grossPayment",
    "cisStatus"
  ],
  "properties": {
    "taxYear": {
      "enum": [
        "2026-27",
        "2025-26",
        "2024-25"
      ],
      "type": "string",
      "description": "UK tax year, e.g. \"2026-27\". Defaults to the current one."
    },
    "expenses": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Expected business expenses for the year"
    },
    "cisStatus": {
      "enum": [
        "registered",
        "unregistered",
        "gross"
      ],
      "type": "string",
      "description": "registered (20%), unregistered (30%) or gross payment status (0%)"
    },
    "annualIncome": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Expected self-employed income for the year"
    },
    "grossPayment": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "The payment before deduction"
    },
    "materialsAmount": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Part of the payment that is materials"
    }
  }
}

calculate_contractor_day_rate

Turn a contractor day rate into annual and monthly income, an hourly equivalent, and take-home pay as a sole trader, through a company outside IR35 and inside IR35, with the best route and the PAYE salary that would take home as much, for a tax year.

read-only

Argument	Type	Description
dayRate*	number	Day rate charged
taxYear	string	UK tax year, e.g. "2026-27". Defaults to the current one.
hoursPerDay	number	Hours in a working day; defaults to 7.5
billableDays*	number	Days billed in a year after holidays, sickness and gaps
accountancyCost	number	Accountancy cost a year
businessExpenses	number	Business expenses a year

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "dayRate",
    "billableDays"
  ],
  "properties": {
    "dayRate": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Day rate charged"
    },
    "taxYear": {
      "enum": [
        "2026-27",
        "2025-26",
        "2024-25"
      ],
      "type": "string",
      "description": "UK tax year, e.g. \"2026-27\". Defaults to the current one."
    },
    "hoursPerDay": {
      "type": "number",
      "maximum": 24,
      "description": "Hours in a working day; defaults to 7.5",
      "exclusiveMinimum": 0
    },
    "billableDays": {
      "type": "number",
      "maximum": 366,
      "description": "Days billed in a year after holidays, sickness and gaps",
      "exclusiveMinimum": 0
    },
    "accountancyCost": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Accountancy cost a year"
    },
    "businessExpenses": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Business expenses a year"
    }
  }
}

calculate_corporation_tax

Calculate UK corporation tax on a company's taxable profit for a tax year, including marginal relief between the small profits and main rates, with profit after tax and the effective rate.

read-only

Argument	Type	Description
taxYear	string	UK tax year, e.g. "2026-27". Defaults to the current one.
taxableProfit*	number	Company's taxable profit for the year

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "taxableProfit"
  ],
  "properties": {
    "taxYear": {
      "enum": [
        "2026-27",
        "2025-26",
        "2024-25"
      ],
      "type": "string",
      "description": "UK tax year, e.g. \"2026-27\". Defaults to the current one."
    },
    "taxableProfit": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Company's taxable profit for the year"
    }
  }
}

calculate_dividend_tax

Calculate UK tax on dividends for a tax year, given the dividends and other income: the dividend allowance, tax at the basic, higher and additional dividend rates, and the effective rate.

read-only

Argument	Type	Description
taxYear	string	UK tax year, e.g. "2026-27". Defaults to the current one.
otherIncome	number	Other taxable income, such as a salary
dividendIncome*	number	Dividends received in the year

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "dividendIncome"
  ],
  "properties": {
    "taxYear": {
      "enum": [
        "2026-27",
        "2025-26",
        "2024-25"
      ],
      "type": "string",
      "description": "UK tax year, e.g. \"2026-27\". Defaults to the current one."
    },
    "otherIncome": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Other taxable income, such as a salary"
    },
    "dividendIncome": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Dividends received in the year"
    }
  }
}

calculate_gross_salary_for_take_home

Work out the gross UK salary needed to take home a given amount a year after income tax, employee National Insurance, student loan and a pension percentage, for a tax year (net to gross).

read-only

Argument	Type	Description
taxYear	string	UK tax year, e.g. "2026-27". Defaults to the current one.
pensionPercent	number	Employee pension as a percentage of gross, e.g. 5
targetTakeHome*	number	Take-home pay wanted a year, in pounds
studentLoanPlan	string	Student loan plan, if any (plan4 is Scotland, postgrad the postgraduate loan)
scottishTaxpayer	boolean	True for a Scottish taxpayer (Scottish bands)

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "targetTakeHome"
  ],
  "properties": {
    "taxYear": {
      "enum": [
        "2026-27",
        "2025-26",
        "2024-25"
      ],
      "type": "string",
      "description": "UK tax year, e.g. \"2026-27\". Defaults to the current one."
    },
    "pensionPercent": {
      "type": "number",
      "maximum": 100,
      "minimum": 0,
      "description": "Employee pension as a percentage of gross, e.g. 5"
    },
    "targetTakeHome": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Take-home pay wanted a year, in pounds"
    },
    "studentLoanPlan": {
      "enum": [
        "none",
        "plan1",
        "plan2",
        "plan4",
        "postgrad"
      ],
      "type": "string",
      "description": "Student loan plan, if any (plan4 is Scotland, postgrad the postgraduate loan)"
    },
    "scottishTaxpayer": {
      "type": "boolean",
      "description": "True for a Scottish taxpayer (Scottish bands)"
    }
  }
}

calculate_invoice_due_date

Calculate the date an invoice is due from its date and the payment terms (on receipt, a number of days, end of month, days after month end, a day of the following month, or the statutory 30-day default), with the weekday and whether the terms exceed the statutory limit.

read-only

Argument	Type	Description
days	integer	Days, for net and net-end-of-month terms
terms*	string	The payment terms
customer	string
dayOfMonth	integer	Day, for day-of-following-month terms
invoiceDate*	string	Invoice date, or the day the customer received it (YYYY-MM-DD)

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "invoiceDate",
    "terms"
  ],
  "properties": {
    "days": {
      "type": "integer",
      "maximum": 365,
      "minimum": 0,
      "description": "Days, for net and net-end-of-month terms"
    },
    "terms": {
      "enum": [
        "on-receipt",
        "net",
        "end-of-month",
        "net-end-of-month",
        "day-of-following-month",
        "statutory-default"
      ],
      "type": "string",
      "description": "The payment terms"
    },
    "customer": {
      "enum": [
        "business",
        "public-authority"
      ],
      "type": "string"
    },
    "dayOfMonth": {
      "type": "integer",
      "maximum": 31,
      "minimum": 1,
      "description": "Day, for day-of-following-month terms"
    },
    "invoiceDate": {
      "type": "string",
      "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
      "description": "Invoice date, or the day the customer received it (YYYY-MM-DD)"
    }
  }
}

calculate_late_payment_interest

Calculate the statutory interest (Bank of England base rate plus 8%) and fixed compensation a business can claim on a late-paid commercial invoice under the Late Payment of Commercial Debts Act, from the amount, the due date and the payment date.

read-only

Argument	Type	Description
amount*	number	Unpaid invoice amount, VAT included if charged
paidOn	string	The day it was paid; defaults to today
dueDate*	string	The last day payment was due

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "amount",
    "dueDate"
  ],
  "properties": {
    "amount": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Unpaid invoice amount, VAT included if charged"
    },
    "paidOn": {
      "type": "string",
      "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
      "description": "The day it was paid; defaults to today"
    },
    "dueDate": {
      "type": "string",
      "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
      "description": "The last day payment was due"
    }
  }
}

calculate_markup

Calculate the selling price, profit and the equivalent profit margin from a cost and a markup percentage.

read-only

Argument	Type	Description
cost*	number	Cost of the item or job
markupPercent*	number	Markup on cost, as a percentage

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "cost",
    "markupPercent"
  ],
  "properties": {
    "cost": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Cost of the item or job"
    },
    "markupPercent": {
      "type": "number",
      "maximum": 100000,
      "minimum": 0,
      "description": "Markup on cost, as a percentage"
    }
  }
}

calculate_mileage_allowance

Calculate the tax-free business mileage allowance for a year at HMRC's approved mileage rates for a car or van, motorcycle or bicycle, including the passenger rate, and the tax it saves at the basic or higher rate.

read-only

Argument	Type	Description
taxBand	string	Income tax band, for the saving; defaults to basic
vehicleType	string	Defaults to car (cars and vans)
passengerTrips	integer	Business trips with a passenger
annualBusinessMiles*	number	Business miles in the year
averageMilesPerPassengerTrip	number

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "annualBusinessMiles"
  ],
  "properties": {
    "taxBand": {
      "enum": [
        "basic",
        "higher"
      ],
      "type": "string",
      "description": "Income tax band, for the saving; defaults to basic"
    },
    "vehicleType": {
      "enum": [
        "car",
        "motorcycle",
        "bicycle"
      ],
      "type": "string",
      "description": "Defaults to car (cars and vans)"
    },
    "passengerTrips": {
      "type": "integer",
      "maximum": 10000,
      "minimum": 0,
      "description": "Business trips with a passenger"
    },
    "annualBusinessMiles": {
      "type": "number",
      "maximum": 500000,
      "minimum": 0,
      "description": "Business miles in the year"
    },
    "averageMilesPerPassengerTrip": {
      "type": "number",
      "maximum": 1000,
      "minimum": 0
    }
  }
}

calculate_pension_tax_relief

Compare a self-employed person's tax with their current and a higher personal pension contribution in a tax year: the basic-rate relief added to the pension, the reduction in the tax bill, and the net cost of the extra contribution.

read-only

Argument	Type	Description
taxYear	string	UK tax year, e.g. "2026-27". Defaults to the current one.
grossIncome*	number	Self-employed income before expenses
businessExpenses	number	Allowable business expenses
targetPensionContribution*	number	Personal pension contributions planned, a year
currentPensionContribution	number	Personal pension contributions now, a year

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "grossIncome",
    "targetPensionContribution"
  ],
  "properties": {
    "taxYear": {
      "enum": [
        "2026-27",
        "2025-26",
        "2024-25"
      ],
      "type": "string",
      "description": "UK tax year, e.g. \"2026-27\". Defaults to the current one."
    },
    "grossIncome": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Self-employed income before expenses"
    },
    "businessExpenses": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Allowable business expenses"
    },
    "targetPensionContribution": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Personal pension contributions planned, a year"
    },
    "currentPensionContribution": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Personal pension contributions now, a year"
    }
  }
}

calculate_pro_rata_salary

Work out a part-time salary from the full-time salary and the hours or days worked compared with full time, with the take-home pay on the pro rata salary for a tax year.

read-only

Argument	Type	Description
taxYear	string	UK tax year, e.g. "2026-27". Defaults to the current one.
actualUnits*	number	Hours (or days) actually worked a week, in the same unit
fullTimeUnits*	number	Full-time hours (or days) a week, e.g. 37.5
fullTimeSalary*	number	Full-time annual salary
studentLoanPlan	string	Student loan plan, if any (plan4 is Scotland, postgrad the postgraduate loan)
scottishTaxpayer	boolean	True for a Scottish taxpayer (Scottish bands)

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "fullTimeSalary",
    "fullTimeUnits",
    "actualUnits"
  ],
  "properties": {
    "taxYear": {
      "enum": [
        "2026-27",
        "2025-26",
        "2024-25"
      ],
      "type": "string",
      "description": "UK tax year, e.g. \"2026-27\". Defaults to the current one."
    },
    "actualUnits": {
      "type": "number",
      "maximum": 168,
      "description": "Hours (or days) actually worked a week, in the same unit",
      "exclusiveMinimum": 0
    },
    "fullTimeUnits": {
      "type": "number",
      "maximum": 168,
      "description": "Full-time hours (or days) a week, e.g. 37.5",
      "exclusiveMinimum": 0
    },
    "fullTimeSalary": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Full-time annual salary"
    },
    "studentLoanPlan": {
      "enum": [
        "none",
        "plan1",
        "plan2",
        "plan4",
        "postgrad"
      ],
      "type": "string",
      "description": "Student loan plan, if any (plan4 is Scotland, postgrad the postgraduate loan)"
    },
    "scottishTaxpayer": {
      "type": "boolean",
      "description": "True for a Scottish taxpayer (Scottish bands)"
    }
  }
}

calculate_profit_margin

Calculate the profit margin and markup from a cost and a selling price, or the selling price needed for a target margin.

read-only

Argument	Type	Description
cost*	number	Cost of the item or job
price	number	Selling price
targetMarginPercent	number	Margin wanted, as a percentage of price

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "cost"
  ],
  "properties": {
    "cost": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Cost of the item or job"
    },
    "price": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Selling price"
    },
    "targetMarginPercent": {
      "type": "number",
      "maximum": 99.99,
      "minimum": 0,
      "description": "Margin wanted, as a percentage of price"
    }
  }
}

calculate_rental_income_tax

Calculate UK income tax on rental profit for a landlord in a tax year, given rent, allowable expenses, mortgage interest (relieved as a 20% tax credit) and other income.

read-only

Argument	Type	Description
taxYear	string	UK tax year, e.g. "2026-27". Defaults to the current one.
grossRent*	number	Rent received in the year
otherIncome	number	Other taxable income
allowableExpenses	number	Allowable expenses, not mortgage interest
mortgageInterestPaid	number	Mortgage interest paid

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "grossRent"
  ],
  "properties": {
    "taxYear": {
      "enum": [
        "2026-27",
        "2025-26",
        "2024-25"
      ],
      "type": "string",
      "description": "UK tax year, e.g. \"2026-27\". Defaults to the current one."
    },
    "grossRent": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Rent received in the year"
    },
    "otherIncome": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Other taxable income"
    },
    "allowableExpenses": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Allowable expenses, not mortgage interest"
    },
    "mortgageInterestPaid": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Mortgage interest paid"
    }
  }
}

calculate_salary_sacrifice

Compare pay before and after a salary sacrifice for a pension or an electric company car: income tax, National Insurance and student loan saved, employer National Insurance saved and passed back, benefit-in-kind tax for a car, the drop in take-home pay, and for a pension the cost per pound added and the saving against paying in from net pay.

read-only

Argument	Type	Description
taxYear	string	UK tax year, e.g. "2026-27". Defaults to the current one.
grossSalary*	number	Gross annual salary before the sacrifice
carP11dValue	number	List (P11D) value of the car; electric car only
sacrificeType*	string	pension, or ev-car for an electric car scheme
sacrificeAmount*	number	Amount given up from gross pay each year
studentLoanPlan	string	Student loan plan, if any (plan4 is Scotland, postgrad the postgraduate loan)
scottishTaxpayer	boolean	True for a Scottish taxpayer (Scottish bands)

calculate_savings_interest_tax

Calculate UK tax on savings interest for a tax year, given the interest, any tax already deducted and other income: the starting rate for savings, the Personal Savings Allowance and the tax due.

read-only

Argument	Type	Description
taxYear	string	UK tax year, e.g. "2026-27". Defaults to the current one.
otherIncome	number	Other taxable income
grossInterest*	number	Savings interest in the year
taxDeductedAtSource	number	Tax already deducted from the interest

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "grossInterest"
  ],
  "properties": {
    "taxYear": {
      "enum": [
        "2026-27",
        "2025-26",
        "2024-25"
      ],
      "type": "string",
      "description": "UK tax year, e.g. \"2026-27\". Defaults to the current one."
    },
    "otherIncome": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Other taxable income"
    },
    "grossInterest": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Savings interest in the year"
    },
    "taxDeductedAtSource": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Tax already deducted from the interest"
    }
  }
}

calculate_stamp_duty

Calculate the tax on buying property: Stamp Duty Land Tax in England and Northern Ireland, Land and Buildings Transaction Tax in Scotland or Land Transaction Tax in Wales, by band, with first-time buyer relief, the additional property surcharge and the non-resident surcharge where they apply.

read-only

Argument	Type	Description
price*	number	Purchase price
company	boolean	True when a company is buying
country	string	Where the property is; defaults to England or Northern Ireland
ukResident	boolean	False adds the non-resident surcharge (England and NI)
propertyUse	string
completionDate	string	Completion date; defaults to today
firstTimeBuyer	boolean
replacingMainResidence	boolean
ownsOtherResidentialProperty

calculate_student_loan_repayment

Calculate yearly, monthly and weekly UK student loan repayments on an income for a repayment plan (Plan 1, 2, 4 or the postgraduate loan) in a tax year.

read-only

Argument	Type	Description
plan*	string	Repayment plan
taxYear	string	UK tax year, e.g. "2026-27". Defaults to the current one.
annualIncome*	number	Income a year that repayments are taken from

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "annualIncome",
    "plan"
  ],
  "properties": {
    "plan": {
      "enum": [
        "plan1",
        "plan2",
        "plan4",
        "postgrad"
      ],
      "type": "string",
      "description": "Repayment plan"
    },
    "taxYear": {
      "enum": [
        "2026-27",
        "2025-26",
        "2024-25"
      ],
      "type": "string",
      "description": "UK tax year, e.g. \"2026-27\". Defaults to the current one."
    },
    "annualIncome": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Income a year that repayments are taken from"
    }
  }
}

calculate_take_home_pay

Calculate take-home pay from a UK salary for a tax year: income tax by band (England, Wales and Northern Ireland, or Scotland), employee National Insurance, student loan repayment and pension contributions, with yearly, monthly and weekly take-home and the employer National Insurance and total cost to the employer.

read-only

Argument	Type	Description
taxYear	string	UK tax year, e.g. "2026-27". Defaults to the current one.
grossSalary*	number	Gross annual salary in pounds
studentLoanPlan	string	Student loan plan, if any (plan4 is Scotland, postgrad the postgraduate loan)
scottishTaxpayer	boolean	True for a Scottish taxpayer (Scottish bands)
pensionContributions	number	Employee pension contributions a year, in pounds

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "grossSalary"
  ],
  "properties": {
    "taxYear": {
      "enum": [
        "2026-27",
        "2025-26",
        "2024-25"
      ],
      "type": "string",
      "description": "UK tax year, e.g. \"2026-27\". Defaults to the current one."
    },
    "grossSalary": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Gross annual salary in pounds"
    },
    "studentLoanPlan": {
      "enum": [
        "none",
        "plan1",
        "plan2",
        "plan4",
        "postgrad"
      ],
      "type": "string",
      "description": "Student loan plan, if any (plan4 is Scotland, postgrad the postgraduate loan)"
    },
    "scottishTaxpayer": {
      "type": "boolean",
      "description": "True for a Scottish taxpayer (Scottish bands)"
    },
    "pensionContributions": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Employee pension contributions a year, in pounds"
    }
  }
}

calculate_tax_on_multiple_incomes

Calculate the combined UK tax on income from several sources in one tax year (employment, self-employment, rental profit, dividends and savings interest), allowing for PAYE tax already deducted: income tax, National Insurance, student loan, what is left to pay and take-home.

read-only

Argument	Type	Description
taxYear	string	UK tax year, e.g. "2026-27". Defaults to the current one.
employment	number	Employment income (salary)
rentalProfit	number	Rental profit
dividendIncome	number	Dividends
selfEmployment	number	Self-employed profit
payeTaxDeducted	number	Income tax already deducted through PAYE
savingsInterest	number	Savings interest
studentLoanPlan	string	Student loan plan, if any (plan4 is Scotland, postgrad the postgraduate loan)
pensionContributions

calculate_vat

Add VAT to a net price or take it out of a gross price at the standard (20%), reduced (5%) or any other rate, with the net, VAT and gross amounts.

read-only

Argument	Type	Description
amount*	number	The price
direction*	string	add: the amount is net; remove: the amount includes VAT
ratePercent	number	VAT rate as a percentage; defaults to 20

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "amount",
    "direction"
  ],
  "properties": {
    "amount": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "The price"
    },
    "direction": {
      "enum": [
        "add",
        "remove"
      ],
      "type": "string",
      "description": "add: the amount is net; remove: the amount includes VAT"
    },
    "ratePercent": {
      "type": "number",
      "maximum": 100,
      "minimum": 0,
      "description": "VAT rate as a percentage; defaults to 20"
    }
  }
}

check_mtd_status

Say whether and when Making Tax Digital for Income Tax applies to someone, from their qualifying income: self-employment turnover plus property income, before expenses, as on their Self Assessment return. Employment and pension income do not count.

read-only

Argument	Type	Description
propertyIncome	number
selfEmploymentTurnover*	number

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "selfEmploymentTurnover"
  ],
  "properties": {
    "propertyIncome": {
      "type": "number",
      "default": 0,
      "maximum": 100000000,
      "minimum": 0
    },
    "selfEmploymentTurnover": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0
    }
  }
}

check_tax_code

Check whether a UK PAYE tax code (e.g. 1257L, BR, K475, 1257L W1/M1) looks right for a salary and circumstances, explain what it means, and estimate any over- or under-payment. Flat-rate codes (BR, D0, D1) are only judged when hasMultipleJobs is known; without it the verdict is needs_info. Returns a verdict tier; refund figures are estimates, not amounts owed.

read-only

Argument	Type	Description
taxCode*	string	The code as printed on a payslip or P45
taxYear	string	Tax year the code applies to; defaults to the current one
scotland	boolean	True for a Scottish taxpayer
grossSalary*	number	Annual gross pay from this job, in pounds
monthsOnCode	integer	For emergency codes: how many monthly payslips were paid on it so far
hasCompanyCar	boolean
hasMultipleJobs	boolean	Whether the person has another job or pension; omitted when unknown
hasPrivateMedical	boolean

check_vat_registration

Check whether a turnover is over the UK VAT registration threshold for a tax year, and compare VAT payable under the standard scheme with the Flat Rate Scheme for the business's sector rate, including the first-year discount, with the cheaper scheme and the difference.

read-only

Argument	Type	Description
taxYear	string	UK tax year, e.g. "2026-27". Defaults to the current one.
annualTurnover*	number	VAT taxable turnover over 12 months
flatRatePercent	number	Flat Rate Scheme percentage for the sector, e.g. 14.5 for IT consultancy
vatablePurchases	number	Purchases with VAT a year
firstYearOfVatRegistration	boolean

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "annualTurnover"
  ],
  "properties": {
    "taxYear": {
      "enum": [
        "2026-27",
        "2025-26",
        "2024-25"
      ],
      "type": "string",
      "description": "UK tax year, e.g. \"2026-27\". Defaults to the current one."
    },
    "annualTurnover": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "VAT taxable turnover over 12 months"
    },
    "flatRatePercent": {
      "type": "number",
      "maximum": 20,
      "minimum": 0,
      "description": "Flat Rate Scheme percentage for the sector, e.g. 14.5 for IT consultancy"
    },
    "vatablePurchases": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Purchases with VAT a year"
    },
    "firstYearOfVatRegistration": {
      "type": "boolean"
    }
  }
}

check_vat_reverse_charge

Work out whether the domestic VAT reverse charge for construction services applies to an invoice, by HMRC's decision steps. Takes the yes or no answers known so far and returns the next question to answer, or the outcome with what the invoice must say.

read-only

Argument	Type	Description
answers	object	Answers so far, keyed by question id: supplier-vat, construction-service, vat-rate, employment-business, customer-vat, customer-cis, end-user, five-percent

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "properties": {
    "answers": {
      "type": "object",
      "description": "Answers so far, keyed by question id: supplier-vat, construction-service, vat-rate, employment-business, customer-vat, customer-cis, end-user, five-percent",
      "propertyNames": {
        "enum": [
          "supplier-vat",
          "construction-service",
          "vat-rate",
          "employment-business",
          "customer-vat",
          "customer-cis",
          "end-user",
          "five-percent"
        ],
        "type": "string"
      },
      "additionalProperties": {
        "type": "boolean"
      }
    }
  }
}

compare_inside_and_outside_ir35

Compare a contractor's take-home pay working inside IR35 (deemed employment payment, employer National Insurance) with working outside IR35 through a limited company, from the day rate and working days, for a tax year. It compares pay; it does not decide IR35 status.

read-only

Argument	Type	Description
dayRate*	number	Day rate charged
taxYear	string	UK tax year, e.g. "2026-27". Defaults to the current one.
workingDays*	number	Days worked in the year
accountancyCost	number	Accountancy cost a year
businessExpenses	number	Business expenses a year

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "dayRate",
    "workingDays"
  ],
  "properties": {
    "dayRate": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Day rate charged"
    },
    "taxYear": {
      "enum": [
        "2026-27",
        "2025-26",
        "2024-25"
      ],
      "type": "string",
      "description": "UK tax year, e.g. \"2026-27\". Defaults to the current one."
    },
    "workingDays": {
      "type": "number",
      "maximum": 366,
      "description": "Days worked in the year",
      "exclusiveMinimum": 0
    },
    "accountancyCost": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Accountancy cost a year"
    },
    "businessExpenses": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Business expenses a year"
    }
  }
}

compare_limited_company_and_sole_trader

Compare take-home pay as a sole trader with running the same profit through a limited company (salary plus dividends, corporation tax and accountancy cost) for a tax year, with the annual difference and an approximate break-even profit.

read-only

Argument	Type	Description
taxYear	string	UK tax year, e.g. "2026-27". Defaults to the current one.
annualProfit*	number	Business profit a year
accountancyCost	number	Extra accountancy cost of a company a year; defaults to 2000

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "annualProfit"
  ],
  "properties": {
    "taxYear": {
      "enum": [
        "2026-27",
        "2025-26",
        "2024-25"
      ],
      "type": "string",
      "description": "UK tax year, e.g. \"2026-27\". Defaults to the current one."
    },
    "annualProfit": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Business profit a year"
    },
    "accountancyCost": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Extra accountancy cost of a company a year; defaults to 2000"
    }
  }
}

compare_salary_and_dividends

For a limited company director, work out take-home pay from a chosen salary plus dividends paid from the remaining profit after employer National Insurance and corporation tax, with every tax and the effective rate, for a tax year.

read-only

Argument	Type	Description
salary*	number	Director's salary for the year
taxYear	string	UK tax year, e.g. "2026-27". Defaults to the current one.
companyProfitBeforeSalary*	number	Company profit before the director's salary

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "companyProfitBeforeSalary",
    "salary"
  ],
  "properties": {
    "salary": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Director's salary for the year"
    },
    "taxYear": {
      "enum": [
        "2026-27",
        "2025-26",
        "2024-25"
      ],
      "type": "string",
      "description": "UK tax year, e.g. \"2026-27\". Defaults to the current one."
    },
    "companyProfitBeforeSalary": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Company profit before the director's salary"
    }
  }
}

convert_hourly_rate_to_salary

Convert an hourly rate to the annual salary it adds up to for the hours a week and paid weeks a year given, with take-home pay on that salary for a tax year.

read-only

Argument	Type	Description
taxYear	string	UK tax year, e.g. "2026-27". Defaults to the current one.
hourlyRate*	number	Gross pay per hour
hoursPerWeek*	number	Hours worked a week
studentLoanPlan	string	Student loan plan, if any (plan4 is Scotland, postgrad the postgraduate loan)
paidWeeksPerYear	number	Paid weeks a year; defaults to 52 (holiday is paid)
scottishTaxpayer	boolean	True for a Scottish taxpayer (Scottish bands)

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "hourlyRate",
    "hoursPerWeek"
  ],
  "properties": {
    "taxYear": {
      "enum": [
        "2026-27",
        "2025-26",
        "2024-25"
      ],
      "type": "string",
      "description": "UK tax year, e.g. \"2026-27\". Defaults to the current one."
    },
    "hourlyRate": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Gross pay per hour"
    },
    "hoursPerWeek": {
      "type": "number",
      "maximum": 100,
      "description": "Hours worked a week",
      "exclusiveMinimum": 0
    },
    "studentLoanPlan": {
      "enum": [
        "none",
        "plan1",
        "plan2",
        "plan4",
        "postgrad"
      ],
      "type": "string",
      "description": "Student loan plan, if any (plan4 is Scotland, postgrad the postgraduate loan)"
    },
    "paidWeeksPerYear": {
      "type": "number",
      "maximum": 52,
      "description": "Paid weeks a year; defaults to 52 (holiday is paid)",
      "exclusiveMinimum": 0
    },
    "scottishTaxpayer": {
      "type": "boolean",
      "description": "True for a Scottish taxpayer (Scottish bands)"
    }
  }
}

convert_salary_to_hourly_rate

Convert an annual salary to its gross hourly rate and the take-home pay per hour, for the hours a week and paid weeks a year given, in a tax year.

read-only

Argument	Type	Description
taxYear	string	UK tax year, e.g. "2026-27". Defaults to the current one.
annualSalary*	number	Gross annual salary
hoursPerWeek*	number	Hours worked a week
studentLoanPlan	string	Student loan plan, if any (plan4 is Scotland, postgrad the postgraduate loan)
paidWeeksPerYear	number	Paid weeks a year; defaults to 52
scottishTaxpayer	boolean	True for a Scottish taxpayer (Scottish bands)

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "annualSalary",
    "hoursPerWeek"
  ],
  "properties": {
    "taxYear": {
      "enum": [
        "2026-27",
        "2025-26",
        "2024-25"
      ],
      "type": "string",
      "description": "UK tax year, e.g. \"2026-27\". Defaults to the current one."
    },
    "annualSalary": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Gross annual salary"
    },
    "hoursPerWeek": {
      "type": "number",
      "maximum": 100,
      "description": "Hours worked a week",
      "exclusiveMinimum": 0
    },
    "studentLoanPlan": {
      "enum": [
        "none",
        "plan1",
        "plan2",
        "plan4",
        "postgrad"
      ],
      "type": "string",
      "description": "Student loan plan, if any (plan4 is Scotland, postgrad the postgraduate loan)"
    },
    "paidWeeksPerYear": {
      "type": "number",
      "maximum": 52,
      "description": "Paid weeks a year; defaults to 52",
      "exclusiveMinimum": 0
    },
    "scottishTaxpayer": {
      "type": "boolean",
      "description": "True for a Scottish taxpayer (Scottish bands)"
    }
  }
}

create_invoice

Create and save a draft invoice in the signed-in person's TapTax account from a client name and one or more line items. No saved client, earlier invoice or client email is needed to create it; an email is only needed later, to send it. It is numbered in their sequence, uses their saved business details, and is not sent. Free plans include 3 invoices; paid plans are unlimited.

Argument	Type	Description
items*	array
notes	string
dueDate	string	Exact due date; otherwise dueInDays applies
dueInDays	integer	Payment terms in days when no dueDate is given (0 = due on receipt)
issueDate	string	Defaults to today
clientName*	string
clientEmail	string	The client email; required to send the invoice
clientAddress	string
vatRatePercent	number	VAT rate for a VAT-registered business, e.g. 20

estimate_self_assessment_penalties

Estimate Self Assessment late filing penalties, late payment penalties and late payment interest on the tax due, from how many days late the return was filed and the tax was paid.

read-only

Argument	Type	Description
taxDue*	number	Tax due on the return
filingDaysLate*	integer	Days after the filing deadline the return was filed
paymentDaysLate*	integer	Days after the payment deadline the tax was paid
annualInterestRatePercent	number	HMRC's late payment interest rate a year; defaults to 7.75

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "taxDue",
    "filingDaysLate",
    "paymentDaysLate"
  ],
  "properties": {
    "taxDue": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Tax due on the return"
    },
    "filingDaysLate": {
      "type": "integer",
      "maximum": 3650,
      "minimum": 0,
      "description": "Days after the filing deadline the return was filed"
    },
    "paymentDaysLate": {
      "type": "integer",
      "maximum": 3650,
      "minimum": 0,
      "description": "Days after the payment deadline the tax was paid"
    },
    "annualInterestRatePercent": {
      "type": "number",
      "maximum": 30,
      "minimum": 0,
      "description": "HMRC's late payment interest rate a year; defaults to 7.75"
    }
  }
}

estimate_self_employed_tax

Estimate UK income tax and Class 4 National Insurance for a sole trader from turnover and allowable expenses, with the take-home figure, effective and marginal rates, payments on account and tailored tips, from HMRC's published rates for the tax year. Works from the figures given, without a TapTax account.

read-only

Argument	Type	Description
taxYear	string	UK tax year, e.g. "2026-27" (6 April 2026 to 5 April 2027). Defaults to the current one.
expenses	number	Allowable business expenses, in pounds (excluding mileage if businessMiles is given)
turnover*	number	Self-employed income before expenses, in pounds
otherIncome	number	Other taxable income such as a salary or pension, in pounds
businessMiles	number	Business miles driven in a car or van, claimed at the approved mileage rate
studentLoanPlan	string
taxDeductedAtSource	number	Tax already paid through PAYE or CIS deductions this year
pensionContributions

generate_invoice_numbers

Generate invoice numbers: the next number after a given one (keeping its prefix and zero padding), or a run of numbers in a chosen format (prefix, separator, optional year or month, number of digits) from a starting number.

read-only

Argument	Type	Description
count	integer	How many; defaults to 1
start	integer	First number; defaults to 1
digits	integer	Digits in the number; defaults to 4
prefix	string	Letters, numbers and single hyphens, e.g. INV
datePart	string
separator	string
lastNumber	string	The last number used, e.g. INV-0041

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "properties": {
    "count": {
      "type": "integer",
      "maximum": 100,
      "minimum": 1,
      "description": "How many; defaults to 1"
    },
    "start": {
      "type": "integer",
      "maximum": 99999999,
      "minimum": 0,
      "description": "First number; defaults to 1"
    },
    "digits": {
      "type": "integer",
      "maximum": 8,
      "minimum": 1,
      "description": "Digits in the number; defaults to 4"
    },
    "prefix": {
      "type": "string",
      "maxLength": 12,
      "description": "Letters, numbers and single hyphens, e.g. INV"
    },
    "datePart": {
      "enum": [
        "none",
        "YYYY",
        "YY",
        "YYYYMM",
        "YYMM"
      ],
      "type": "string"
    },
    "separator": {
      "enum": [
        "-",
        "/",
        ".",
        ""
      ],
      "type": "string"
    },
    "lastNumber": {
      "type": "string",
      "maxLength": 60,
      "minLength": 1,
      "description": "The last number used, e.g. INV-0041"
    }
  }
}

get_mileage_summary

Read the signed-in person's own mileage log in their TapTax account for a tax year: total miles, the deductible amount at the approved rates, and the most recent trips.

read-only

Argument	Type	Description
taxYear	string

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "properties": {
    "taxYear": {
      "enum": [
        "2024-25",
        "2025-26",
        "2026-27"
      ],
      "type": "string"
    }
  }
}

get_mtd_deadlines

List the standard Making Tax Digital quarterly update periods and deadlines for a tax year, and which one is next. Updates are cumulative from 6 April.

read-only

Argument	Type	Description
taxYear	string	Defaults to the current tax year

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "properties": {
    "taxYear": {
      "enum": [
        "2024-25",
        "2025-26",
        "2026-27"
      ],
      "type": "string",
      "description": "Defaults to the current tax year"
    }
  }
}

get_tax_position

Read the signed-in person's own TapTax account: their tax year so far, as their dashboard shows it: business income, expenses and profit counted by the filing rule, the estimated income tax and Class 4 NI, how many transactions still need a business-or-personal decision, which quarterly updates they have filed through TapTax, and the next deadline. Needs no figures from the person: everything comes from their records.

read-only

Argument	Type	Description
taxYear	string	Defaults to the current tax year

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "properties": {
    "taxYear": {
      "enum": [
        "2024-25",
        "2025-26",
        "2026-27"
      ],
      "type": "string",
      "description": "Defaults to the current tax year"
    }
  }
}

list_invoices

Read the signed-in person's own invoices from their TapTax account, newest first, with each one's live status (a sent invoice past its due date reads as overdue) and the totals outstanding and overdue. Needs no details from the person.

read-only

Argument	Type	Description
limit	integer
status	string	unpaid = sent, viewed or overdue

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "properties": {
    "limit": {
      "type": "integer",
      "default": 25,
      "maximum": 100,
      "minimum": 1
    },
    "status": {
      "enum": [
        "all",
        "unpaid",
        "overdue",
        "paid",
        "draft"
      ],
      "type": "string",
      "default": "all",
      "description": "unpaid = sent, viewed or overdue"
    }
  }
}

list_transactions

Read and search the signed-in person's own income and expense records in their TapTax account, newest first. Filter by tax year or dates, type, text in the description, or needsReview=true for the ones still waiting for a business-or-personal decision (the review queue). Needs no details from the person beyond what to look for.

read-only

Argument	Type	Description
to	string	On or before this date
from	string	On or after this date
type	string
limit	integer
search	string	Text to find in the description
taxYear	string
needsReview	boolean

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "properties": {
    "to": {
      "type": "string",
      "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
      "description": "On or before this date"
    },
    "from": {
      "type": "string",
      "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
      "description": "On or after this date"
    },
    "type": {
      "enum": [
        "income",
        "expense"
      ],
      "type": "string"
    },
    "limit": {
      "type": "integer",
      "default": 25,
      "maximum": 100,
      "minimum": 1
    },
    "search": {
      "type": "string",
      "maxLength": 100,
      "minLength": 2,
      "description": "Text to find in the description"
    },
    "taxYear": {
      "enum": [
        "2024-25",
        "2025-26",
        "2026-27"
      ],
      "type": "string"
    },
    "needsReview": {
      "type": "boolean"
    }
  }
}

log_mileage_trip

Record a business journey in the signed-in person's mileage log. TapTax prices it at the approved mileage rate for the tax year (tiered after 10,000 car miles). Commuting to a permanent workplace is not business mileage. Mileage tracking is on the Pro plan.

Argument	Type	Description
to*	string
date*	string
from*	string
miles*	number	Business miles for this trip
purpose*	string
vehicle	string	Vans count as car

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "date",
    "from",
    "to",
    "miles",
    "purpose"
  ],
  "properties": {
    "to": {
      "type": "string",
      "maxLength": 200,
      "minLength": 1
    },
    "date": {
      "type": "string",
      "pattern": "^\\d{4}-\\d{2}-\\d{2}$"
    },
    "from": {
      "type": "string",
      "maxLength": 200,
      "minLength": 1
    },
    "miles": {
      "type": "number",
      "maximum": 99999,
      "description": "Business miles for this trip",
      "exclusiveMinimum": 0
    },
    "purpose": {
      "type": "string",
      "maxLength": 500,
      "minLength": 1
    },
    "vehicle": {
      "enum": [
        "car",
        "motorcycle",
        "bicycle"
      ],
      "type": "string",
      "default": "car",
      "description": "Vans count as car"
    }
  }
}

mark_invoice_paid

Record that the client has paid an invoice (dated today). Stops any payment reminders.

destructive

Argument	Type	Description
invoiceId*	string

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "invoiceId"
  ],
  "properties": {
    "invoiceId": {
      "type": "string",
      "format": "uuid",
      "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|ffffffff-ffff-ffff-ffff-ffffffffffff)$"
    }
  }
}

plan_quarterly_tax_set_aside

Plan how much to set aside for tax as a sole trader under Making Tax Digital, from the year's profit or each quarter's profit: the income tax, Class 4 National Insurance and student loan due, monthly and weekly amounts to put away, running totals by quarter with each update deadline, and any first payment on account.

read-only

Argument	Type	Description
annualProfit	number	Expected profit for the year (split evenly across quarters)
studentLoanPlan	string	Student loan plan, if any
quarterlyProfits	array	Profit for each quarter, Q1 to Q4, instead of an annual figure
firstYearOfTrading	boolean	True in the first year, when the first payment on account is also due

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "properties": {
    "annualProfit": {
      "type": "number",
      "maximum": 100000000,
      "minimum": 0,
      "description": "Expected profit for the year (split evenly across quarters)"
    },
    "studentLoanPlan": {
      "enum": [
        "none",
        "plan1",
        "plan2"
      ],
      "type": "string",
      "description": "Student loan plan, if any"
    },
    "quarterlyProfits": {
      "type": "array",
      "items": {
        "type": "number",
        "maximum": 100000000,
        "minimum": 0,
        "description": "Profit for the quarter"
      },
      "maxItems": 4,
      "minItems": 4,
      "description": "Profit for each quarter, Q1 to Q4, instead of an annual figure"
    },
    "firstYearOfTrading": {
      "type": "boolean",
      "description": "True in the first year, when the first payment on account is also due"
    }
  }
}

prepare_business_document

Prepare an invoice, quote, receipt, credit note or pro forma invoice in TapTax's free document generator, without a TapTax account. Returns the totals and a link that opens the generator with the document filled in, where the person checks it, adds a logo if they like, and downloads the PDF. The details travel in the link itself and are not stored by TapTax.

read-only

Argument	Type	Description
date	string	Issue date, YYYY-MM-DD; defaults to today
kind*	string	Which document
lines*	array
notes	string
number	string	Document number, e.g. INV-0042
fromName	string	The business issuing it
template	string	Design; defaults to the generator default
clientName	string
clientEmail	string

prepare_quarterly_update

Get the signed-in person's Making Tax Digital quarterly update ready: the cumulative income, expenses and profit from 6 April to the end of the quarter, what still needs reviewing, and a card with a button that opens TapTax to check and file it. Filing itself always happens in the TapTax app, never from the chat, so HMRC receives the details of the device the person files from.

read-only

Argument	Type	Description
quarter	integer	1 = to 5 July, 2 = to 5 October, 3 = to 5 January, 4 = to 5 April
taxYear	string	Defaults to the current tax year

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "properties": {
    "quarter": {
      "type": "integer",
      "maximum": 4,
      "minimum": 1,
      "description": "1 = to 5 July, 2 = to 5 October, 3 = to 5 January, 4 = to 5 April"
    },
    "taxYear": {
      "enum": [
        "2024-25",
        "2025-26",
        "2026-27"
      ],
      "type": "string",
      "description": "Defaults to the current tax year"
    }
  }
}

send_invoice

Get one of the signed-in person’s invoices ready to email, with its PDF, to the client address on it from their business name. It opens a card showing exactly what the client will receive (who it goes to, the lines and the total) with a Send button. Nothing is emailed until the person presses Send on that card.

Argument	Type	Description
invoiceId*	string

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "invoiceId"
  ],
  "properties": {
    "invoiceId": {
      "type": "string",
      "format": "uuid",
      "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|ffffffff-ffff-ffff-ffff-ffffffffffff)$"
    }
  }
}

send_invoice_from_card

Emails the invoice shown on a TapTax send card to its client, when the person presses Send on that card. Needs the one-time token the card was given.

destructive

Argument	Type	Description
invoiceId*	string
sendToken*	string

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "invoiceId",
    "sendToken"
  ],
  "properties": {
    "invoiceId": {
      "type": "string",
      "format": "uuid",
      "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|ffffffff-ffff-ffff-ffff-ffffffffffff)$"
    },
    "sendToken": {
      "type": "string",
      "maxLength": 256,
      "minLength": 1
    }
  }
}

update_transaction

Change a transaction the signed-in person owns: mark it business or personal (this is how the review queue is cleared), or correct its category, description, amount or date.

destructive

Argument	Type	Description
id*	string
date	string
amount	number
category	string
description	string
businessOrPersonal	string

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "id"
  ],
  "properties": {
    "id": {
      "type": "string",
      "format": "uuid",
      "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|ffffffff-ffff-ffff-ffff-ffffffffffff)$"
    },
    "date": {
      "type": "string",
      "pattern": "^\\d{4}-\\d{2}-\\d{2}$"
    },
    "amount": {
      "type": "number",
      "maximum": 10000000,
      "exclusiveMinimum": 0
    },
    "category": {
      "enum": [
        "costOfGoods",
        "constructionIndustryScheme",
        "staffCosts",
        "travelCosts",
        "premisesRunningCosts",
        "maintenanceCosts",
        "adminCosts",
        "advertisingCosts",
        "businessEntertainmentCosts",
        "interest",
        "financialCharges",
        "badDebt",
        "professionalFees",
        "depreciation",
        "other",
        "turnover"
      ],
      "type": "string"
    },
    "description": {
      "type": "string",
      "maxLength": 500,
      "minLength": 1
    },
    "businessOrPersonal": {
      "enum": [
        "business",
        "personal"
      ],
      "type": "string"
    }
  }
}

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "clientName",
    "items"
  ],
  "properties": {
    "items": {
      "type": "array",
      "items": {
        "type": "object",
        "required": [
          "description",
          "unitPrice"
        ],
        "properties": {
          "quantity": {
            "type": "number",
            "default": 1,
            "maximum": 99999,
            "exclusiveMinimum": 0
          },
          "unitPrice": {
            "type": "number",
            "maximum": 10000000,
            "minimum": 0,
            "description": "In pounds, before VAT"
          },
          "description": {
            "type": "string",
            "maxLength": 500,
            "minLength": 1
          }
        }
      },
      "maxItems": 50,
      "minItems": 1
    },
    "notes": {
      "type": "string",
      "maxLength": 2000
    },
    "dueDate": {
      "type": "string",
      "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
      "description": "Exact due date; otherwise dueInDays applies"
    },
    "dueInDays": {
      "type": "integer",
      "default": 30,
      "maximum": 120,
      "minimum": 0,
      "description": "Payment terms in days when no dueDate is given (0 = due on receipt)"
    },
    "issueDate": {
      "type": "string",
      "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
      "description": "Defaults to today"
    },
    "clientName": {
      "type": "string",
      "maxLength": 200,
      "minLength": 1
    },
    "clientEmail": {
      "type": "string",
      "format": "email",
      "pattern": "^(?!\\.)(?!.*\\.\\.)([A-Za-z0-9_'+\\-\\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\\-]*\\.)+[A-Za-z]{2,}$",
      "description": "The client email; required to send the invoice"
    },
    "clientAddress": {
      "type": "string",
      "maxLength": 500
    },
    "vatRatePercent": {
      "type": "number",
      "maximum": 100,
      "minimum": 0,
      "description": "VAT rate for a VAT-registered business, e.g. 20"
    }
  }
}

Input schema (JSON)

{
  "type": "object",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "required": [
    "kind",
    "lines"
  ],
  "properties": {
    "date": {
      "type": "string",
      "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
      "description": "Issue date, YYYY-MM-DD; defaults to today"
    },
    "kind": {
      "enum": [
        "invoice",
        "quote",
        "receipt",
        "credit_note",
        "proforma_invoice"
      ],
      "type": "string",
      "description": "Which document"
    },
    "lines": {
      "type": "array",
      "items": {
        "type": "object",
        "required": [
          "description",
          "quantity",
          "unitPrice"
        ],
        "properties": {
          "unit": {
            "enum": [
              "item",
              "hour",
              "day",
              "week",
              "month",
              "job",
              "mile"
            ],
            "type": "string",
            "description": "Defaults to item"
          },
          "quantity": {
            "type": "number",
            "maximum": 99999,
            "exclusiveMinimum": 0
          },
          "unitPrice": {
            "type": "number",
            "maximum": 10000000,
            "minimum": 0,
            "description": "In pounds, before VAT"
          },
          "description": {
            "type": "string",
            "maxLength": 200,
            "minLength": 1
          }
        }
      },
      "maxItems": 20,
      "minItems": 1
    },
    "notes": {
      "type": "string",
      "maxLength": 1000
    },
    "number": {
      "type": "string",
      "maxLength": 40,
      "description": "Document number, e.g. INV-0042"
    },
    "fromName": {
      "type": "string",
      "maxLength": 200,
      "description": "The business issuing it"
    },
    "template": {
      "enum": [
        "classic",
        "plain",
        "trades",
        "consultancy",
        "creative",
        "retail"
      ],
      "type": "string",
      "description": "Design; defaults to the generator default"
    },
    "clientName": {
      "type": "string",
      "maxLength": 200
    },
    "clientEmail": {
      "type": "string",
      "format": "email",
      "pattern": "^(?!\\.)(?!.*\\.\\.)([A-Za-z0-9_'+\\-\\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\\-]*\\.)+[A-Za-z]{2,}$"
    },
    "fromAddress": {
      "type": "string",
      "maxLength": 500
    },
    "paymentTerms": {
      "type": "string",
      "maxLength": 300
    },
    "clientAddress": {
      "type": "string",
      "maxLength": 500
    },
    "vatRatePercent": {
      "anyOf": [
        {
          "type": "number",
          "const": 0
        },
        {
          "type": "number",
          "const": 5
        },
        {
          "type": "number",
          "const": 20
        }
      ],
      "description": "Defaults to 0"
    }
  }
}