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 APIEmployer 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 APIPayroll
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 APIStatutory 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 APIContractors
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 APIReference 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/ratesEvery rate and threshold for a tax yearGET /v1/tax-yearsThe tax years supportedGET /v1/tax-codes/{code}What a tax code meansGET /openapi.jsonThe 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.