# TapTax (remote · api.taptax.co.uk) UK tax: take-home pay, self-employed and company tax, VAT, stamp duty, invoices and MTD. - Trust score: 69/100 (medium) - Registry status: active - Liveness: live - Owner verified: no - Last scored: 2026-10-07 ## Components - remote · `api.taptax.co.uk`: 69/100 (this document), [markdown](https://verifymcp.io/servers/uk-co-taptax-taptax/api.md), [page](https://verifymcp.io/servers/uk-co-taptax-taptax/api) ## Channel facts - Endpoint: `https://api.taptax.co.uk/mcp` - Transports: `streamable-http` - Auth: `none` - Version: `1.1.0` ## Trust breakdown How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog) Scored 2026-10-07. - **Endpoint Security**: 66/100 - The endpoint's TLS certificate is valid, in date, and uses a strong key. - Authorisation check failed: no authorisation is required to call this server, and it exposes a tool marked destructive (update_transaction). - HTTPS is enforced; there's no plaintext access path. - The HSTS (Strict-Transport-Security) header is present. - DNSSEC is configured correctly; the domain's records validate against the full chain to the root. - **Transport & Reachability**: 100/100 - Verified streamable-http transport via a live MCP handshake. - **Schema Quality & AI Usability**: 78/100 - 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name). - AI-judged instruction clarity (good). - Context-footprint check failed: tool/resource definitions use about 7034 tokens (~143/item across 49 items; 48 tools + 1 resources), over budget; trim descriptions and params. - Usage-examples check failed: none of the tools include examples. - **Stability & Change Management**: 13/100 - Stability observed for 4 of 30 days with no destabilising changes; credit accrues until the full window elapses. - **Tool Coverage**: 93/100 - 100% of tools have a non-trivial description (not blank, and not just the tool's name). - 80% of tool parameters carry a description. - **Tool Safety**: 81/100 - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured. - 1 of 4 tool(s) whose name or description implies an irreversible operation declare an MCP destructiveHint annotation; "calculate_take_home_pay" implies "pay" and declares readOnlyHint instead, contradicting what its own name says it does. - An AI judge read all 50 captured unit(s) of tool text and found none that tries to manipulate the model reading it. - **Capabilities**: 100/100 - Implements a current MCP spec version (2026-07-28). - Supports UI / widget rendering. ## Install ### How do I install the TapTax MCP server? TapTax is a hosted endpoint at https://api.taptax.co.uk/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation. ### Claude ```bash claude mcp add --transport http uk-co-taptax-taptax 'https://api.taptax.co.uk/mcp' ``` ### Cursor ```json { "mcpServers": { "uk-co-taptax-taptax": { "url": "https://api.taptax.co.uk/mcp" } } } ``` ### VS Code ```json { "servers": { "uk-co-taptax-taptax": { "type": "http", "url": "https://api.taptax.co.uk/mcp" } } } ``` ### Codex ```toml [mcp_servers.uk-co-taptax-taptax] url = "https://api.taptax.co.uk/mcp" ``` ### opencode ```json { "$schema": "https://opencode.ai/config.json", "mcp": { "uk-co-taptax-taptax": { "type": "remote", "url": "https://api.taptax.co.uk/mcp", "enabled": true } } } ``` ### OpenClaw ```bash openclaw mcp add uk-co-taptax-taptax --url 'https://api.taptax.co.uk/mcp' --transport streamable-http ``` ### Hermes ```yaml mcp_servers: uk-co-taptax-taptax: url: "https://api.taptax.co.uk/mcp" ``` ### Netclaw ```json { "McpServers": { "uk-co-taptax-taptax": { "Transport": "http", "Url": "https://api.taptax.co.uk/mcp" } } } ``` ### Vellum ```bash assistant mcp add uk-co-taptax-taptax -t streamable-http -u 'https://api.taptax.co.uk/mcp' ``` ### Other ```json { "mcpServers": { "uk-co-taptax-taptax": { "type": "http", "url": "https://api.taptax.co.uk/mcp" } } } ``` The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs. ## Changelog Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims. ### 2026-10-07 (score 69, +2) - [security improvement] DNSSEC: fail → pass ### 2026-10-05 (score 67, +1) - [security] Tool “create_invoice” rewrote its description, which is the text the model reads - [security] Tool “get_mileage_summary” rewrote its description, which is the text the model reads - [security] Tool “get_tax_position” rewrote its description, which is the text the model reads - [security] Tool “list_invoices” rewrote its description, which is the text the model reads - [security] Tool “list_transactions” rewrote its description, which is the text the model reads - [cosmetic] “calculate_capital_gains_tax” added an optional parameter “disposalDate” ### 2026-10-04 (score 66, −1) - [functional regression] Schema quality: 2235 → 6911 - [functional improvement] Tool coverage: 52% → 80% - [functional improvement] Stability: unverified → 0.03 - [functional] Schema quality: excellent → good - [functional] Destructive annotations: 1 of 4 tool(s) whose name or description implies an irreversible operation declare an MCP destructiveHint annotation; "calculate_take_home_pay" implies "pay" and declares readOnlyHint instead, contradicting what its own name says it does. - [functional] Server version: 1.0.0 → 1.1.0 - [functional] New tool “calculate_tax_on_multiple_incomes” - [functional] New tool “calculate_capital_gains_tax” - [functional] New tool “calculate_child_benefit_charge” - [functional] New tool “calculate_cis_deduction” - [functional] New tool “calculate_contractor_day_rate” - [functional] New tool “calculate_corporation_tax” - [functional] New tool “calculate_dividend_tax” - [functional] New tool “calculate_gross_salary_for_take_home” - [functional] New tool “calculate_invoice_due_date” - [functional] New tool “calculate_late_payment_interest” - [functional] New tool “calculate_markup” - [functional] New tool “calculate_mileage_allowance” - [functional] New tool “calculate_pension_tax_relief” - [functional] New tool “calculate_pro_rata_salary” - [functional] New tool “calculate_profit_margin” - [functional] New tool “calculate_rental_income_tax” - [functional] New tool “calculate_salary_sacrifice” - [functional] New tool “calculate_savings_interest_tax” - [functional] New tool “calculate_stamp_duty” - [functional] New tool “calculate_student_loan_repayment” - [functional] New tool “calculate_take_home_pay” - [functional] New tool “calculate_vat” - [functional] New tool “check_vat_registration” - [functional] New tool “check_vat_reverse_charge” - [functional] New tool “compare_inside_and_outside_ir35” - [functional] New tool “compare_limited_company_and_sole_trader” - [functional] New tool “compare_salary_and_dividends” - [functional] New tool “convert_hourly_rate_to_salary” - [functional] New tool “convert_salary_to_hourly_rate” - [functional] New tool “estimate_self_assessment_penalties” - [functional] New tool “generate_invoice_numbers” - [functional] New tool “plan_quarterly_tax_set_aside” - [functional] New tool “prepare_business_document” ### 2026-10-03 (score 67) First indexed and scored. ## MCP tools (49) ### `estimate_self_employed_tax` (~245 tokens) 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. Input parameters: - `businessMiles` (number): Business miles driven in a car or van, claimed at the approved mileage rate - `expenses` (number): Allowable business expenses, in pounds (excluding mileage if businessMiles is given) - `otherIncome` (number): Other taxable income such as a salary or pension, in pounds - `pensionContributions` (number): Personal pension contributions paid (relief at source), in pounds - `studentLoanPlan` (string) - `taxDeductedAtSource` (number): Tax already paid through PAYE or CIS deductions this year - `taxYear` (string): UK tax year, e.g. "2026-27" (6 April 2026 to 5 April 2027). Defaults to the current one. - `turnover` (number, required): Self-employed income before expenses, in pounds ### `check_tax_code` (~267 tokens) Check a PAYE 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. Input parameters: - `grossSalary` (number, required): Annual gross pay from this job, in pounds - `hasCompanyCar` (boolean) - `hasMarriageAllowance` (boolean) - `hasMultipleJobs` (boolean): Whether the person has another job or pension; omitted when unknown - `hasPrivateMedical` (boolean) - `marriageAllowanceDirection` (string) - `monthsOnCode` (integer): For emergency codes: how many monthly payslips were paid on it so far - `receivesStatePension` (boolean) - `scotland` (boolean): True for a Scottish taxpayer - `taxCode` (string, required): The code as printed on a payslip or P45 - `taxYear` (string): Tax year the code applies to; defaults to the current one ### `check_mtd_status` (~73 tokens) Check if Making Tax Digital applies 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. Input parameters: - `propertyIncome` (number) - `selfEmploymentTurnover` (number, required) ### `get_mtd_deadlines` (~55 tokens) Making Tax Digital 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. Input parameters: - `taxYear` (string): Defaults to the current tax year ### `calculate_take_home_pay` (~171 tokens) 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. Input parameters: - `grossSalary` (number, required): Gross annual salary in pounds - `pensionContributions` (number): Employee pension contributions a year, in pounds - `scottishTaxpayer` (boolean): True for a Scottish taxpayer (Scottish bands) - `studentLoanPlan` (string): Student loan plan, if any (plan4 is Scotland, postgrad the postgraduate loan) - `taxYear` (string): UK tax year, e.g. "2026-27". Defaults to the current one. ### `calculate_gross_salary_for_take_home` (~163 tokens) Work out the salary for a take-home figure 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). Input parameters: - `pensionPercent` (number): Employee pension as a percentage of gross, e.g. 5 - `scottishTaxpayer` (boolean): True for a Scottish taxpayer (Scottish bands) - `studentLoanPlan` (string): Student loan plan, if any (plan4 is Scotland, postgrad the postgraduate loan) - `targetTakeHome` (number, required): Take-home pay wanted a year, in pounds - `taxYear` (string): UK tax year, e.g. "2026-27". Defaults to the current one. ### `calculate_salary_sacrifice` (~255 tokens) Calculate salary sacrifice savings 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. Input parameters: - `carP11dValue` (number): List (P11D) value of the car; electric car only - `employerNIPassback` (number): Share (0 to 1) of the employer NI saving added to the pension; pension only - `grossSalary` (number, required): Gross annual salary before the sacrifice - `sacrificeAmount` (number, required): Amount given up from gross pay each year - `sacrificeType` (string, required): pension, or ev-car for an electric car scheme - `scottishTaxpayer` (boolean): True for a Scottish taxpayer (Scottish bands) - `studentLoanPlan` (string): Student loan plan, if any (plan4 is Scotland, postgrad the postgraduate loan) - `taxYear` (string): UK tax year, e.g. "2026-27". Defaults to the current one. ### `calculate_pro_rata_salary` (~181 tokens) Calculate a 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. Input parameters: - `actualUnits` (number, required): Hours (or days) actually worked a week, in the same unit - `fullTimeSalary` (number, required): Full-time annual salary - `fullTimeUnits` (number, required): Full-time hours (or days) a week, e.g. 37.5 - `scottishTaxpayer` (boolean): True for a Scottish taxpayer (Scottish bands) - `studentLoanPlan` (string): Student loan plan, if any (plan4 is Scotland, postgrad the postgraduate loan) - `taxYear` (string): UK tax year, e.g. "2026-27". Defaults to the current one. ### `convert_hourly_rate_to_salary` (~168 tokens) Convert an hourly rate to a 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. Input parameters: - `hourlyRate` (number, required): Gross pay per hour - `hoursPerWeek` (number, required): Hours worked a week - `paidWeeksPerYear` (number): Paid weeks a year; defaults to 52 (holiday is paid) - `scottishTaxpayer` (boolean): True for a Scottish taxpayer (Scottish bands) - `studentLoanPlan` (string): Student loan plan, if any (plan4 is Scotland, postgrad the postgraduate loan) - `taxYear` (string): UK tax year, e.g. "2026-27". Defaults to the current one. ### `convert_salary_to_hourly_rate` (~161 tokens) Convert a salary to an 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. Input parameters: - `annualSalary` (number, required): Gross annual salary - `hoursPerWeek` (number, required): Hours worked a week - `paidWeeksPerYear` (number): Paid weeks a year; defaults to 52 - `scottishTaxpayer` (boolean): True for a Scottish taxpayer (Scottish bands) - `studentLoanPlan` (string): Student loan plan, if any (plan4 is Scotland, postgrad the postgraduate loan) - `taxYear` (string): UK tax year, e.g. "2026-27". Defaults to the current one. ### `calculate_student_loan_repayment` (~101 tokens) Calculate student loan repayments 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. Input parameters: - `annualIncome` (number, required): Income a year that repayments are taken from - `plan` (string, required): Repayment plan - `taxYear` (string): UK tax year, e.g. "2026-27". Defaults to the current one. ### `calculate_child_benefit_charge` (~110 tokens) Calculate the High Income 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. Input parameters: - `adjustedNetIncome` (number, required): The higher earner's adjusted net income for the year - `annualChildBenefit` (number, required): Child Benefit received in the year - `taxYear` (string): UK tax year, e.g. "2026-27". Defaults to the current one. ### `calculate_tax_on_multiple_incomes` (~203 tokens) Calculate tax on several 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. Input parameters: - `dividendIncome` (number): Dividends - `employment` (number): Employment income (salary) - `payeTaxDeducted` (number): Income tax already deducted through PAYE - `pensionContributions` (number): Personal pension contributions - `rentalProfit` (number): Rental profit - `savingsInterest` (number): Savings interest - `selfEmployment` (number): Self-employed profit - `studentLoanPlan` (string): Student loan plan, if any (plan4 is Scotland, postgrad the postgraduate loan) - `taxYear` (string): UK tax year, e.g. "2026-27". Defaults to the current one. ### `calculate_pension_tax_relief` (~142 tokens) 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. Input parameters: - `businessExpenses` (number): Allowable business expenses - `currentPensionContribution` (number): Personal pension contributions now, a year - `grossIncome` (number, required): Self-employed income before expenses - `targetPensionContribution` (number, required): Personal pension contributions planned, a year - `taxYear` (string): UK tax year, e.g. "2026-27". Defaults to the current one. ### `calculate_dividend_tax` (~104 tokens) 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. Input parameters: - `dividendIncome` (number, required): Dividends received in the year - `otherIncome` (number): Other taxable income, such as a salary - `taxYear` (string): UK tax year, e.g. "2026-27". Defaults to the current one. ### `compare_salary_and_dividends` (~111 tokens) 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. Input parameters: - `companyProfitBeforeSalary` (number, required): Company profit before the director's salary - `salary` (number, required): Director's salary for the year - `taxYear` (string): UK tax year, e.g. "2026-27". Defaults to the current one. ### `compare_limited_company_and_sole_trader` (~122 tokens) Compare a 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. Input parameters: - `accountancyCost` (number): Extra accountancy cost of a company a year; defaults to 2000 - `annualProfit` (number, required): Business profit a year - `taxYear` (string): UK tax year, e.g. "2026-27". Defaults to the current one. ### `calculate_corporation_tax` (~85 tokens) 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. Input parameters: - `taxYear` (string): UK tax year, e.g. "2026-27". Defaults to the current one. - `taxableProfit` (number, required): Company's taxable profit for the year ### `calculate_contractor_day_rate` (~171 tokens) Calculate contractor day rate income 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. Input parameters: - `accountancyCost` (number): Accountancy cost a year - `billableDays` (number, required): Days billed in a year after holidays, sickness and gaps - `businessExpenses` (number): Business expenses a year - `dayRate` (number, required): Day rate charged - `hoursPerDay` (number): Hours in a working day; defaults to 7.5 - `taxYear` (string): UK tax year, e.g. "2026-27". Defaults to the current one. ### `compare_inside_and_outside_ir35` (~145 tokens) 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. Input parameters: - `accountancyCost` (number): Accountancy cost a year - `businessExpenses` (number): Business expenses a year - `dayRate` (number, required): Day rate charged - `taxYear` (string): UK tax year, e.g. "2026-27". Defaults to the current one. - `workingDays` (number, required): Days worked in the year ### `calculate_cis_deduction` (~166 tokens) Calculate a 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. Input parameters: - `annualIncome` (number): Expected self-employed income for the year - `cisStatus` (string, required): registered (20%), unregistered (30%) or gross payment status (0%) - `expenses` (number): Expected business expenses for the year - `grossPayment` (number, required): The payment before deduction - `materialsAmount` (number): Part of the payment that is materials - `taxYear` (string): UK tax year, e.g. "2026-27". Defaults to the current one. ### `plan_quarterly_tax_set_aside` (~162 tokens) Plan how much tax to 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. Input parameters: - `annualProfit` (number): Expected profit for the year (split evenly across quarters) - `firstYearOfTrading` (boolean): True in the first year, when the first payment on account is also due - `quarterlyProfits` (array): Profit for each quarter, Q1 to Q4, instead of an annual figure - `studentLoanPlan` (string): Student loan plan, if any ### `calculate_mileage_allowance` (~127 tokens) Calculate the 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. Input parameters: - `annualBusinessMiles` (number, required): Business miles in the year - `averageMilesPerPassengerTrip` (number) - `passengerTrips` (integer): Business trips with a passenger - `taxBand` (string): Income tax band, for the saving; defaults to basic - `vehicleType` (string): Defaults to car (cars and vans) ### `estimate_self_assessment_penalties` (~121 tokens) 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. Input parameters: - `annualInterestRatePercent` (number): HMRC's late payment interest rate a year; defaults to 7.75 - `filingDaysLate` (integer, required): Days after the filing deadline the return was filed - `paymentDaysLate` (integer, required): Days after the payment deadline the tax was paid - `taxDue` (number, required): Tax due on the return ### `calculate_vat` (~94 tokens) Add or remove 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. Input parameters: - `amount` (number, required): The price - `direction` (string, required): add: the amount is net; remove: the amount includes VAT - `ratePercent` (number): VAT rate as a percentage; defaults to 20 ### `check_vat_registration` (~156 tokens) Check VAT registration and the Flat Rate Scheme 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. Input parameters: - `annualTurnover` (number, required): VAT taxable turnover over 12 months - `firstYearOfVatRegistration` (boolean) - `flatRatePercent` (number): Flat Rate Scheme percentage for the sector, e.g. 14.5 for IT consultancy - `taxYear` (string): UK tax year, e.g. "2026-27". Defaults to the current one. - `vatablePurchases` (number): Purchases with VAT a year ### `check_vat_reverse_charge` (~103 tokens) Check the construction 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. Input parameters: - `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 ### `calculate_markup` (~56 tokens) Calculate a price from a markup Calculate the selling price, profit and the equivalent profit margin from a cost and a markup percentage. Input parameters: - `cost` (number, required): Cost of the item or job - `markupPercent` (number, required): Markup on cost, as a percentage ### `calculate_profit_margin` (~72 tokens) Calculate a profit margin Calculate the profit margin and markup from a cost and a selling price, or the selling price needed for a target margin. Input parameters: - `cost` (number, required): Cost of the item or job - `price` (number): Selling price - `targetMarginPercent` (number): Margin wanted, as a percentage of price ### `calculate_invoice_due_date` (~143 tokens) Calculate an 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. Input parameters: - `customer` (string) - `dayOfMonth` (integer): Day, for day-of-following-month terms - `days` (integer): Days, for net and net-end-of-month terms - `invoiceDate` (string, required): Invoice date, or the day the customer received it (YYYY-MM-DD) - `terms` (string, required): The payment terms ### `calculate_late_payment_interest` (~107 tokens) Calculate late payment interest on an invoice 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. Input parameters: - `amount` (number, required): Unpaid invoice amount, VAT included if charged - `dueDate` (string, required): The last day payment was due - `paidOn` (string): The day it was paid; defaults to today ### `calculate_capital_gains_tax` (~208 tokens) 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. Input parameters: - `allowableCosts` (number): Costs of buying, improving and selling - `assetType` (string, required): badr: Business Asset Disposal Relief - `costBasis` (number, required): What the asset cost - `disposalDate` (string): Disposal date; only matters in 2024-25, when rates changed on 30 October 2024 - `losses` (number): Capital losses to offset - `otherIncome` (number): Taxable income in the year, which sets the rate - `proceeds` (number, required): Sale proceeds - `taxYear` (string): UK tax year, e.g. "2026-27". Defaults to the current one. ### `calculate_rental_income_tax` (~126 tokens) Calculate tax on rental income 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. Input parameters: - `allowableExpenses` (number): Allowable expenses, not mortgage interest - `grossRent` (number, required): Rent received in the year - `mortgageInterestPaid` (number): Mortgage interest paid - `otherIncome` (number): Other taxable income - `taxYear` (string): UK tax year, e.g. "2026-27". Defaults to the current one. ### `calculate_savings_interest_tax` (~118 tokens) Calculate tax on savings interest 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. Input parameters: - `grossInterest` (number, required): Savings interest in the year - `otherIncome` (number): Other taxable income - `taxDeductedAtSource` (number): Tax already deducted from the interest - `taxYear` (string): UK tax year, e.g. "2026-27". Defaults to the current one. ### `calculate_stamp_duty` (~178 tokens) 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. Input parameters: - `company` (boolean): True when a company is buying - `completionDate` (string): Completion date; defaults to today - `country` (string): Where the property is; defaults to England or Northern Ireland - `firstTimeBuyer` (boolean) - `ownsOtherResidentialProperty` (boolean): Drives the additional property surcharge - `price` (number, required): Purchase price - `propertyUse` (string) - `replacingMainResidence` (boolean) - `ukResident` (boolean): False adds the non-resident surcharge (England and NI) ### `prepare_business_document` (~220 tokens) Prepare an invoice, quote or receipt to download 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. Input parameters: - `clientAddress` (string) - `clientEmail` (string) - `clientName` (string) - `date` (string): Issue date, YYYY-MM-DD; defaults to today - `fromAddress` (string) - `fromName` (string): The business issuing it - `kind` (string, required): Which document - `lines` (array, required) - `notes` (string) - `number` (string): Document number, e.g. INV-0042 - `paymentTerms` (string) - `template` (string): Design; defaults to the generator default - `vatRatePercent`: Defaults to 0 ### `generate_invoice_numbers` (~156 tokens) 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. Input parameters: - `count` (integer): How many; defaults to 1 - `datePart` (string) - `digits` (integer): Digits in the number; defaults to 4 - `lastNumber` (string): The last number used, e.g. INV-0041 - `prefix` (string): Letters, numbers and single hyphens, e.g. INV - `separator` (string) - `start` (integer): First number; defaults to 1 ### `get_tax_position` (~107 tokens) Get my 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. Input parameters: - `taxYear` (string): Defaults to the current tax year ### `list_transactions` (~143 tokens) List my 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. Input parameters: - `from` (string): On or after this date - `limit` (integer) - `needsReview` (boolean) - `search` (string): Text to find in the description - `taxYear` (string) - `to` (string): On or before this date - `type` (string) ### `get_mileage_summary` (~53 tokens) Get my mileage 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. Input parameters: - `taxYear` (string) ### `add_transaction` (~476 tokens) Add income or an expense 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. Input parameters: - `amount` (number, required): In pounds, VAT included - `category` (string, 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 Elect… - `date` (string, required): The date on the receipt or of the payment - `description` (string, required): Supplier or client, and what it was for - `personal` (boolean): True for a personal (non-business) payment - `type` (string, required) ### `update_transaction` (~87 tokens) Update or review a 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. Input parameters: - `amount` (number) - `businessOrPersonal` (string) - `category` (string) - `date` (string) - `description` (string) - `id` (string, required) ### `log_mileage_trip` (~117 tokens) Log a business 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. Input parameters: - `date` (string, required) - `from` (string, required) - `miles` (number, required): Business miles for this trip - `purpose` (string, required) - `to` (string, required) - `vehicle` (string): Vans count as car ### `list_invoices` (~77 tokens) List my 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. Input parameters: - `limit` (integer) - `status` (string): unpaid = sent, viewed or overdue ### `create_invoice` (~212 tokens) Create an 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. Input parameters: - `clientAddress` (string) - `clientEmail` (string): The client email; required to send the invoice - `clientName` (string, required) - `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 - `items` (array, required) - `notes` (string) - `vatRatePercent` (number): VAT rate for a VAT-registered business, e.g. 20 ### `send_invoice` (~84 tokens) Email an invoice to the client 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. Input parameters: - `invoiceId` (string, required) ### `send_invoice_from_card` (~59 tokens) Send the invoice shown on the 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. Input parameters: - `invoiceId` (string, required) - `sendToken` (string, required) ### `mark_invoice_paid` (~34 tokens) Mark an invoice paid Record that the client has paid an invoice (dated today). Stops any payment reminders. Input parameters: - `invoiceId` (string, required) ### `prepare_quarterly_update` (~143 tokens) Prepare my 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. Input parameters: - `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 ## Diagnostics Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/uk-co-taptax-taptax/api#diagnostics ## Score history - 2026-10-07: 69 - 2026-10-05: 67 - 2026-10-04: 66 - 2026-10-03: 67 ## Common questions ### What is the TapTax MCP server? TapTax is an MCP server listed in the public MCP registry as uk.co.taptax/taptax. UK tax: take-home pay, self-employed and company tax, VAT, stamp duty, invoices and MTD. This page covers its hosted endpoint (https://api.taptax.co.uk/mcp). ### Is the TapTax MCP server safe to use? TapTax scores 69 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm. ### What tools does the TapTax MCP server expose? TapTax exposes 49 tools: estimate_self_employed_tax, check_tax_code, check_mtd_status, get_mtd_deadlines, calculate_take_home_pay, and 44 more. Their descriptions and schemas cost roughly 6,938 tokens of context every time the server is loaded. ### Does the TapTax MCP server require authentication? No. We connected to TapTax without credentials and it answered, so anything it exposes is reachable by anyone who knows the address. ### Is the TapTax MCP server still maintained? TapTax is still listed as active in the MCP registry. We last reached this channel on 7 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced. ## Links - Remote endpoint: https://api.taptax.co.uk/mcp - Website: https://taptax.co.uk/integrations/claude - Changelog RSS feed: https://verifymcp.io/servers/uk-co-taptax-taptax/api.xml - Changelog JSON feed: https://verifymcp.io/servers/uk-co-taptax-taptax/api.json - HTML version of this page: https://verifymcp.io/servers/uk-co-taptax-taptax/api