> One API for UK take-home pay, gross from net, employer cost, payroll periods, statutory pay and contractor tax, tested against HMRC’s own payroll test data.

Web version: https://checktakehomepay.co.uk/api · Last updated: 2026-10-09

# UK pay calculations, as an API

Take-home pay, gross from net, employer cost, payroll periods, statutory pay and contractor tax, worked out the way HMRC and payroll software do. Money comes back in pounds and pence, with the tax year, the engine and the HMRC test data that produced it, the assumptions made and the gov.uk sources.

## Take-home pay

An API for UK take-home pay: income tax, NI, student loans and pensions for 2026/27, worked out the way payroll does, with gross from net.

[UK take-home pay API](https://checktakehomepay.co.uk/take-home-pay-api)

## Employer cost

An API for what an employee costs: employer NI, Employment Allowance, the auto-enrolment pension minimum, Class 1A NI and the Apprenticeship Levy.

[Employer cost of employment API](https://checktakehomepay.co.uk/employer-cost-api)

## Payroll

An API that runs one UK pay period like payroll software: cumulative or week 1/month 1 tax, NI by category letter, directors’ NI and student loans.

[Payroll calculation API](https://checktakehomepay.co.uk/payroll-api)

## Statutory pay

An API for UK statutory pay: SSP, SMP, SAP, SPP, ShPP, bereavement and neonatal care pay, plus redundancy, notice, holiday and minimum wage checks.

[Statutory pay and entitlements API](https://checktakehomepay.co.uk/statutory-pay-api)

## Contractors

An API for contractors and the self-employed: Class 4 NI, a director’s salary and dividends, umbrella company pay and inside against outside IR35.

[Contractor and self-employed tax API](https://checktakehomepay.co.uk/contractor-tax-api)

## Reference data needs no key

Rates, tax years and tax code decoding are free and unmetered, so assistants and agents can use them without signing up.

-   `GET /v1/rates`Every rate and threshold for a tax year
-   `GET /v1/tax-years`The tax years supported
-   `GET /v1/tax-codes/{code}`What a tax code means
-   `GET /openapi.json`The OpenAPI document

## One request

```
curl https://api.checktakehomepay.co.uk/v1/take-home \
  -H "Authorization: Bearer $CHECKTAKEHOMEPAY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "gross": {
    "amount": 45000,
    "per": "year"
  },
  "region": "england",
  "student_loans": [
    "plan_2"
  ],
  "pension": {
    "method": "salary_sacrifice",
    "percent": 5,
    "basis": "qualifying_earnings"
  }
}'
```

## Every endpoint on every plan

Plans differ only in how many calculations a month.

[Get an API key](https://checktakehomepay.co.uk/login)[Read the quickstart](https://checktakehomepay.co.uk/docs/quickstart)