TapTax

What TapTax MCP server does

TapTax MCP server exposes UK tax and bookkeeping capabilities through the Model Context Protocol. It is aimed at sole traders, landlords, employees, contractors, company directors and developers building assistants around UK tax workflows. The server is listed in the Official MCP Registry as uk.co.taptax/taptax and is hosted by TapTax, so the repository provides connection details and client plugins rather than a local application.

Public calculations cover self-employed tax, PAYE tax codes, take-home pay, salary sacrifice, student loans, dividends, corporation tax, IR35 comparisons, CIS deductions, mileage, penalties, VAT, markup, profit margins and invoice due dates. Other public tools cover MTD eligibility and deadlines, rental income, savings interest, capital gains, stamp duty, business documents and invoice numbers.

These capabilities place TapTax MCP server in the 💰 Finance & Fintech category. Estimates are based on the figures supplied and are not tax advice.

How it works

Connect an MCP client to https://api.taptax.co.uk/mcp using Streamable HTTP. The 37 public tools require no account or authentication. They calculate or explain results from supplied inputs, including tax-year assumptions, income sources, expenses, rates and payment details.

Eleven additional tools work with a user’s TapTax account. They can read tax position, transactions, mileage and invoices, and can add or update transactions, log trips, create or prepare invoices, mark invoices paid and prepare a quarterly update. These account tools use OAuth 2.1 with PKCE and supported client registration methods. The user selects read-only or read-and-change access on sign-in.

TapTax MCP server does not submit a quarterly update to HMRC. Instead, it presents the figures and opens TapTax on the relevant period so the user completes the final action. Invoice sending also requires the user to press Send. The service does not move money or reveal bank or HMRC credentials.

Setup and configuration

There are no local packages, processes or environment variables to configure. Add the hosted URL to an MCP client that supports Streamable HTTP. Claude users can add the connector; Claude Code and Cursor have repository plugins or direct server configuration, and VS Code can add the same HTTP endpoint.

For Claude Code, the repository documents a marketplace installation or the equivalent HTTP command. Cursor can use its marketplace plugin or an mcp.json entry containing the server URL. Other MCP clients can point directly to the endpoint. Account operations trigger authorization in clients that support MCP authorization.

Tools and capabilities

• Estimate self-employed income tax, Class 4 National Insurance, payments on account and take-home pay.
• Calculate salary, pension, student loan, dividend, corporation tax and multiple-income outcomes.
• Check MTD status, quarterly deadlines, VAT registration and construction reverse-charge decisions.
• Compare sole-trader and limited-company routes, salary and dividends, and inside- versus outside-IR35 pay.
• Calculate mileage, CIS deductions, penalties, invoice dates, markup, margins and VAT-inclusive prices.
• Read and update TapTax transactions, mileage, invoices and quarterly-update data after authorization.

Limitations and notes

Results are estimates or calculations, not professional tax advice. Flat-rate PAYE codes such as BR, D0 and D1 need multiple-job information for a definitive assessment. IR35 comparison tools compare pay and do not decide employment status. HMRC filing remains a user action, and sending an invoice requires explicit confirmation in TapTax.

The repository contains registry metadata and ready-made Claude Code and Cursor plugins; the MCP service itself is hosted remotely. TapTax MCP server therefore depends on access to the TapTax endpoint and, for account features, a user’s authorization.