TapTax
REMOTE · API.TAPTAX.CO.UK · SCANNED OCT 7
UK tax: take-home pay, self-employed and company tax, VAT, stamp duty, invoices and MTD.
Available components
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. How we score → Why this is hard to score →
Endpoint Security66
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- Authorisation check failed: no authorisation is required to call this server, and it exposes a tool marked destructive (update_transaction). See how to fix → View diagnostics → Fail
- HTTPS is enforced; there's no plaintext access path. View diagnostics → Pass
- The HSTS (Strict-Transport-Security) header is present. View diagnostics → Pass
- DNSSEC is configured correctly; the domain's records validate against the full chain to the root. View diagnostics → Pass
Transport & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability78
- 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).Pass
- AI-judged instruction clarity (good).Pass
- 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. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management13
- Stability observed for 4 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage93
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 80% of tool parameters carry a description.Partial
Tool Safety81
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- 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. See how to fix → Partial
- An AI judge read all 50 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a current MCP spec version (2026-07-28).Pass
- Supports UI / widget rendering.Pass
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.
remote · api.taptax.co.uk
claude mcp add --transport http uk-co-taptax-taptax 'https://api.taptax.co.uk/mcp'
{
"mcpServers": {
"uk-co-taptax-taptax": {
"url": "https://api.taptax.co.uk/mcp"
}
}
} {
"servers": {
"uk-co-taptax-taptax": {
"type": "http",
"url": "https://api.taptax.co.uk/mcp"
}
}
} [mcp_servers.uk-co-taptax-taptax] url = "https://api.taptax.co.uk/mcp"
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"uk-co-taptax-taptax": {
"type": "remote",
"url": "https://api.taptax.co.uk/mcp",
"enabled": true
}
}
} openclaw mcp add uk-co-taptax-taptax --url 'https://api.taptax.co.uk/mcp' --transport streamable-http
mcp_servers:
uk-co-taptax-taptax:
url: "https://api.taptax.co.uk/mcp" {
"McpServers": {
"uk-co-taptax-taptax": {
"Transport": "http",
"Url": "https://api.taptax.co.uk/mcp"
}
}
} assistant mcp add uk-co-taptax-taptax -t streamable-http -u 'https://api.taptax.co.uk/mcp'
{
"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.
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 7 Oct 26 +2
- DNSSEC: fail → pass ▲ security
- 5 Oct 26 +1
- 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 security
- “calculate_capital_gains_tax” added an optional parameter “disposalDate” cosmetic
- 4 Oct 26 −1
- Schema quality: 2235 → 6911 ▼ functional
- Tool coverage: 52% → 80% ▲ functional
- 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” functional
- 3 Oct 26 67
First indexed and scored.
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 8 Oct 2026 · Probed https://api.taptax.co.uk/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=taptax.co.uk | CN=WE1,O=Google Trust Services,C=US | 28 Aug 2026 | 26 Nov 2026 | ECDSA 256 | ECDSA-SHA256 | 4e351366101092240ebc42c9ef4a0780 |
| SANs: taptax.co.uk, *.taptax.co.uk | ||||||
| CN=WE1,O=Google Trust Services,C=US (CA) | CN=GTS Root R4,O=Google Trust Services LLC,C=US | 13 Dec 2023 | 20 Feb 2029 | ECDSA 256 | ECDSA-SHA384 | 7ff31977972c224a76155d13b6d685e3 |
| CN=GTS Root R4,O=Google Trust Services LLC,C=US (CA) | CN=GlobalSign Root CA,OU=Root CA,O=GlobalSign nv-sa,C=BE | 15 Nov 2023 | 28 Jan 2028 | ECDSA 384 | SHA256-RSA | 7fe530bf331343bedd821610493d8a1b |
Background: What to check on a remote MCP endpoint →
DNSSEC secure
Validation of api.taptax.co.uk. — Secure
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| uk. | present | 43876 | 8 | Verified |
| co.uk. | present | 11810 | 8 | Verified |
| taptax.co.uk. | present | 2371 | 13 | Verified |
| api.taptax.co.uk. | Verified address RRset verified with the apex keys |
Authentication No authorisation required
The endpoint answered without asking for a token. Anyone who knows the URL can reach it.
| Result | No authorisation required |
|---|---|
| HTTP status | 200 |
| Header | Value |
|---|---|
| strict-transport-security | max-age=31536000; includeSubDomains |
| content-security-policy | default-src 'self';base-uri 'self';font-src 'self' https: data:;form-action 'self';frame-ancestors 'self';img-src 'self' data:;object-src 'none';script-src 'self';script-src-attr 'none';style-src 'self' https: 'unsafe-inline';upgrade-insecure-requests |
| x-content-type-options | nosniff |
| x-frame-options | SAMEORIGIN |
| referrer-policy | no-referrer |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://api.taptax.co.uk/mcp | Verified | 200 | |
| http (plaintext) | http://api.taptax.co.uk/mcp | HTTPS enforced | 301 | https://api.taptax.co.uk/mcp |
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
add_transaction Add income or an expense ~476
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.
| Name | Type | Req | Description |
|---|---|---|---|
| amount | number | yes | In pounds, VAT included |
| category | string | yes | 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 | yes | The date on the receipt or of the payment |
| description | string | yes | Supplier or client, and what it was for |
| personal | boolean | – | True for a personal (non-business) payment |
| type | string | yes | – |
No output schema declared.
No examples provided.
calculate_capital_gains_tax Calculate Capital Gains Tax ~208
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.
| Name | Type | Req | Description |
|---|---|---|---|
| allowableCosts | number | – | Costs of buying, improving and selling |
| assetType | string | yes | badr: Business Asset Disposal Relief |
| costBasis | number | yes | 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 | yes | Sale proceeds |
| taxYear | string | – | UK tax year, e.g. "2026-27". Defaults to the current one. |
No output schema declared.
No examples provided.
calculate_child_benefit_charge Calculate the High Income Child Benefit Charge ~110
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.
| Name | Type | Req | Description |
|---|---|---|---|
| adjustedNetIncome | number | yes | The higher earner's adjusted net income for the year |
| annualChildBenefit | number | yes | Child Benefit received in the year |
| taxYear | string | – | UK tax year, e.g. "2026-27". Defaults to the current one. |
No output schema declared.
No examples provided.
calculate_cis_deduction Calculate a CIS deduction ~166
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.
| Name | Type | Req | Description |
|---|---|---|---|
| annualIncome | number | – | Expected self-employed income for the year |
| cisStatus | string | yes | registered (20%), unregistered (30%) or gross payment status (0%) |
| expenses | number | – | Expected business expenses for the year |
| grossPayment | number | yes | 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. |
No output schema declared.
No examples provided.
calculate_contractor_day_rate Calculate contractor day rate income ~171
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.
| Name | Type | Req | Description |
|---|---|---|---|
| accountancyCost | number | – | Accountancy cost a year |
| billableDays | number | yes | Days billed in a year after holidays, sickness and gaps |
| businessExpenses | number | – | Business expenses a year |
| dayRate | number | yes | 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. |
No output schema declared.
No examples provided.
calculate_corporation_tax Calculate corporation tax ~85
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.
| Name | Type | Req | Description |
|---|---|---|---|
| taxYear | string | – | UK tax year, e.g. "2026-27". Defaults to the current one. |
| taxableProfit | number | yes | Company's taxable profit for the year |
No output schema declared.
No examples provided.
calculate_dividend_tax Calculate dividend tax ~104
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.
| Name | Type | Req | Description |
|---|---|---|---|
| dividendIncome | number | yes | 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. |
No output schema declared.
No examples provided.
calculate_gross_salary_for_take_home Work out the salary for a take-home figure ~163
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).
| Name | Type | Req | Description |
|---|---|---|---|
| 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 | yes | Take-home pay wanted a year, in pounds |
| taxYear | string | – | UK tax year, e.g. "2026-27". Defaults to the current one. |
No output schema declared.
No examples provided.
calculate_invoice_due_date Calculate an invoice due date ~143
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.
| Name | Type | Req | Description |
|---|---|---|---|
| customer | string | – | – |
| dayOfMonth | integer | – | Day, for day-of-following-month terms |
| days | integer | – | Days, for net and net-end-of-month terms |
| invoiceDate | string | yes | Invoice date, or the day the customer received it (YYYY-MM-DD) |
| terms | string | yes | The payment terms |
No output schema declared.
No examples provided.
calculate_late_payment_interest Calculate late payment interest on an invoice ~107
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.
| Name | Type | Req | Description |
|---|---|---|---|
| amount | number | yes | Unpaid invoice amount, VAT included if charged |
| dueDate | string | yes | The last day payment was due |
| paidOn | string | – | The day it was paid; defaults to today |
No output schema declared.
No examples provided.
calculate_markup Calculate a price from a markup ~56
Calculate the selling price, profit and the equivalent profit margin from a cost and a markup percentage.
| Name | Type | Req | Description |
|---|---|---|---|
| cost | number | yes | Cost of the item or job |
| markupPercent | number | yes | Markup on cost, as a percentage |
No output schema declared.
No examples provided.
calculate_mileage_allowance Calculate the mileage allowance ~127
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.
| Name | Type | Req | Description |
|---|---|---|---|
| annualBusinessMiles | number | yes | 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) |
No output schema declared.
No examples provided.
calculate_pension_tax_relief Calculate pension tax relief ~142
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.
| Name | Type | Req | Description |
|---|---|---|---|
| businessExpenses | number | – | Allowable business expenses |
| currentPensionContribution | number | – | Personal pension contributions now, a year |
| grossIncome | number | yes | Self-employed income before expenses |
| targetPensionContribution | number | yes | Personal pension contributions planned, a year |
| taxYear | string | – | UK tax year, e.g. "2026-27". Defaults to the current one. |
No output schema declared.
No examples provided.
calculate_pro_rata_salary Calculate a pro rata salary ~181
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.
| Name | Type | Req | Description |
|---|---|---|---|
| actualUnits | number | yes | Hours (or days) actually worked a week, in the same unit |
| fullTimeSalary | number | yes | Full-time annual salary |
| fullTimeUnits | number | yes | 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. |
No output schema declared.
No examples provided.
calculate_profit_margin Calculate a profit margin ~72
Calculate the profit margin and markup from a cost and a selling price, or the selling price needed for a target margin.
| Name | Type | Req | Description |
|---|---|---|---|
| cost | number | yes | Cost of the item or job |
| price | number | – | Selling price |
| targetMarginPercent | number | – | Margin wanted, as a percentage of price |
No output schema declared.
No examples provided.
calculate_rental_income_tax Calculate tax on rental income ~126
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.
| Name | Type | Req | Description |
|---|---|---|---|
| allowableExpenses | number | – | Allowable expenses, not mortgage interest |
| grossRent | number | yes | 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. |
No output schema declared.
No examples provided.
calculate_salary_sacrifice Calculate salary sacrifice savings ~255
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.
| Name | Type | Req | Description |
|---|---|---|---|
| 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 | yes | Gross annual salary before the sacrifice |
| sacrificeAmount | number | yes | Amount given up from gross pay each year |
| sacrificeType | string | yes | 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. |
No output schema declared.
No examples provided.
calculate_savings_interest_tax Calculate tax on savings interest ~118
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.
| Name | Type | Req | Description |
|---|---|---|---|
| grossInterest | number | yes | 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. |
No output schema declared.
No examples provided.
calculate_stamp_duty Calculate Stamp Duty ~178
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.
| Name | Type | Req | Description |
|---|---|---|---|
| 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 | yes | Purchase price |
| propertyUse | string | – | – |
| replacingMainResidence | boolean | – | – |
| ukResident | boolean | – | False adds the non-resident surcharge (England and NI) |
No output schema declared.
No examples provided.
calculate_student_loan_repayment Calculate student loan repayments ~101
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.
| Name | Type | Req | Description |
|---|---|---|---|
| annualIncome | number | yes | Income a year that repayments are taken from |
| plan | string | yes | Repayment plan |
| taxYear | string | – | UK tax year, e.g. "2026-27". Defaults to the current one. |
No output schema declared.
No examples provided.
calculate_take_home_pay Calculate take-home pay ~171
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.
| Name | Type | Req | Description |
|---|---|---|---|
| grossSalary | number | yes | 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. |
No output schema declared.
No examples provided.
calculate_tax_on_multiple_incomes Calculate tax on several incomes ~203
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.
| Name | Type | Req | Description |
|---|---|---|---|
| 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. |
No output schema declared.
No examples provided.
calculate_vat Add or remove VAT ~94
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.
| Name | Type | Req | Description |
|---|---|---|---|
| amount | number | yes | The price |
| direction | string | yes | add: the amount is net; remove: the amount includes VAT |
| ratePercent | number | – | VAT rate as a percentage; defaults to 20 |
No output schema declared.
No examples provided.
check_mtd_status Check if Making Tax Digital applies ~73
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.
| Name | Type | Req | Description |
|---|---|---|---|
| propertyIncome | number | – | – |
| selfEmploymentTurnover | number | yes | – |
No output schema declared.
No examples provided.
check_tax_code Check a PAYE tax code ~267
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.
| Name | Type | Req | Description |
|---|---|---|---|
| grossSalary | number | yes | 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 | yes | The code as printed on a payslip or P45 |
| taxYear | string | – | Tax year the code applies to; defaults to the current one |
No output schema declared.
No examples provided.
check_vat_registration Check VAT registration and the Flat Rate Scheme ~156
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.
| Name | Type | Req | Description |
|---|---|---|---|
| annualTurnover | number | yes | 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 |
No output schema declared.
No examples provided.
check_vat_reverse_charge Check the construction VAT reverse charge ~103
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.
| Name | Type | Req | 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 |
No output schema declared.
No examples provided.
compare_inside_and_outside_ir35 Compare inside and outside IR35 ~145
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.
| Name | Type | Req | Description |
|---|---|---|---|
| accountancyCost | number | – | Accountancy cost a year |
| businessExpenses | number | – | Business expenses a year |
| dayRate | number | yes | Day rate charged |
| taxYear | string | – | UK tax year, e.g. "2026-27". Defaults to the current one. |
| workingDays | number | yes | Days worked in the year |
No output schema declared.
No examples provided.
compare_limited_company_and_sole_trader Compare a limited company and sole trader ~122
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.
| Name | Type | Req | Description |
|---|---|---|---|
| accountancyCost | number | – | Extra accountancy cost of a company a year; defaults to 2000 |
| annualProfit | number | yes | Business profit a year |
| taxYear | string | – | UK tax year, e.g. "2026-27". Defaults to the current one. |
No output schema declared.
No examples provided.
compare_salary_and_dividends Compare salary and dividends ~111
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.
| Name | Type | Req | Description |
|---|---|---|---|
| companyProfitBeforeSalary | number | yes | Company profit before the director's salary |
| salary | number | yes | Director's salary for the year |
| taxYear | string | – | UK tax year, e.g. "2026-27". Defaults to the current one. |
No output schema declared.
No examples provided.
convert_hourly_rate_to_salary Convert an hourly rate to a salary ~168
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.
| Name | Type | Req | Description |
|---|---|---|---|
| hourlyRate | number | yes | Gross pay per hour |
| hoursPerWeek | number | yes | 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. |
No output schema declared.
No examples provided.
convert_salary_to_hourly_rate Convert a salary to an hourly rate ~161
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.
| Name | Type | Req | Description |
|---|---|---|---|
| annualSalary | number | yes | Gross annual salary |
| hoursPerWeek | number | yes | 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. |
No output schema declared.
No examples provided.
create_invoice Create an invoice ~212
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.
| Name | Type | Req | Description |
|---|---|---|---|
| clientAddress | string | – | – |
| clientEmail | string | – | The client email; required to send the invoice |
| clientName | string | yes | – |
| 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 | yes | – |
| notes | string | – | – |
| vatRatePercent | number | – | VAT rate for a VAT-registered business, e.g. 20 |
No output schema declared.
No examples provided.
estimate_self_assessment_penalties Estimate Self Assessment penalties ~121
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.
| Name | Type | Req | Description |
|---|---|---|---|
| annualInterestRatePercent | number | – | HMRC's late payment interest rate a year; defaults to 7.75 |
| filingDaysLate | integer | yes | Days after the filing deadline the return was filed |
| paymentDaysLate | integer | yes | Days after the payment deadline the tax was paid |
| taxDue | number | yes | Tax due on the return |
No output schema declared.
No examples provided.
estimate_self_employed_tax Estimate self-employed tax ~245
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.
| Name | Type | Req | Description |
|---|---|---|---|
| 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 | yes | Self-employed income before expenses, in pounds |
No output schema declared.
No examples provided.
generate_invoice_numbers Generate invoice numbers ~156
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.
| Name | Type | Req | Description |
|---|---|---|---|
| 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 |
No output schema declared.
No examples provided.
get_mileage_summary Get my mileage ~53
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.
| Name | Type | Req | Description |
|---|---|---|---|
| taxYear | string | – | – |
No output schema declared.
No examples provided.
get_mtd_deadlines Making Tax Digital deadlines ~55
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.
| Name | Type | Req | Description |
|---|---|---|---|
| taxYear | string | – | Defaults to the current tax year |
No output schema declared.
No examples provided.
get_tax_position Get my tax position ~107
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.
| Name | Type | Req | Description |
|---|---|---|---|
| taxYear | string | – | Defaults to the current tax year |
No output schema declared.
No examples provided.
list_invoices List my invoices ~77
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.
| Name | Type | Req | Description |
|---|---|---|---|
| limit | integer | – | – |
| status | string | – | unpaid = sent, viewed or overdue |
No output schema declared.
No examples provided.
list_transactions List my transactions ~143
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.
| Name | Type | Req | Description |
|---|---|---|---|
| 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 | – | – |
No output schema declared.
No examples provided.
log_mileage_trip Log a business trip ~117
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.
| Name | Type | Req | Description |
|---|---|---|---|
| date | string | yes | – |
| from | string | yes | – |
| miles | number | yes | Business miles for this trip |
| purpose | string | yes | – |
| to | string | yes | – |
| vehicle | string | – | Vans count as car |
No output schema declared.
No examples provided.
mark_invoice_paid Mark an invoice paid ~34
Record that the client has paid an invoice (dated today). Stops any payment reminders.
| Name | Type | Req | Description |
|---|---|---|---|
| invoiceId | string | yes | – |
No output schema declared.
No examples provided.
plan_quarterly_tax_set_aside Plan how much tax to set aside ~162
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.
| Name | Type | Req | Description |
|---|---|---|---|
| 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 |
No output schema declared.
No examples provided.
prepare_business_document Prepare an invoice, quote or receipt to download ~220
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.
| Name | Type | Req | Description |
|---|---|---|---|
| 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 | yes | Which document |
| lines | array | yes | – |
| notes | string | – | – |
| number | string | – | Document number, e.g. INV-0042 |
| paymentTerms | string | – | – |
| template | string | – | Design; defaults to the generator default |
| vatRatePercent | – | – | Defaults to 0 |
No output schema declared.
No examples provided.
prepare_quarterly_update Prepare my quarterly update ~143
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.
| Name | Type | Req | 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 |
No output schema declared.
No examples provided.
send_invoice Email an invoice to the client ~84
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.
| Name | Type | Req | Description |
|---|---|---|---|
| invoiceId | string | yes | – |
No output schema declared.
No examples provided.
send_invoice_from_card Send the invoice shown on the card ~59
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.
| Name | Type | Req | Description |
|---|---|---|---|
| invoiceId | string | yes | – |
| sendToken | string | yes | – |
No output schema declared.
No examples provided.
update_transaction Update or review a transaction ~87
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.
| Name | Type | Req | Description |
|---|---|---|---|
| amount | number | – | – |
| businessOrPersonal | string | – | – |
| category | string | – | – |
| date | string | – | – |
| description | string | – | – |
| id | string | yes | – |
No output schema declared.
No examples provided.
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.