True Take-HomeOpen data for UK payroll

UK tax rates, as JSON

Income tax bands for England, Wales and Scotland, National Insurance thresholds and all five student loan plans — one file per tax year, free to use commercially with attribution.

Every UK payroll project starts by hard-coding the bands into a constants file, and every April that file is quietly wrong. This is that file, kept current and versioned, so you can fetch it instead.

Use it

curl https://hadidevlabx.github.io/uk-tax-rates/data/latest.json

Pin to a tax year when you need a calculation to stay reproducible:

fetch('https://cdn.jsdelivr.net/gh/HadiDevLabx/uk-tax-rates@v1.0.1/data/2026-27.json')
  .then(r => r.json())
  .then(d => {
    d.incomeTax.personalAllowance      // 12570
    d.incomeTax.bands.scotland         // 6 bands
    d.studentLoans.find(p => p.key === 'plan5').threshold  // 25000
  })

Which URL to use

What is in each file

Each block, applied

Reading a threshold is easy; knowing what it does to a real salary is the part that takes a while. Every row below is the same figure from this dataset worked through on a live calculator — useful for sanity-checking your own implementation against a reference, which is what most of the bug reports on payroll code turn out to need.

Tax years

Where the figures come from

Each file carries a meta.primarySource pointing at the gov.uk or gov.scot page the figures were read from, and a meta.reviewedOn date saying when that was last checked. They are generated from the rate tables behind True Take-Home, a free UK take-home pay calculator, whose build fails rather than serve a stale tax year — so the data here cannot silently drift past an April.

If you want the same figures applied to an actual salary rather than as raw constants, the calculator at truetakehome.co.uk does that, and truetakehome.co.uk/rates.json serves the current year live from the same source.

Common questions

Is there an official HMRC API for tax rates?

No. HMRC's developer hub covers submission — RTI, Making Tax Digital, PAYE returns — not the rate tables themselves. There is no official endpoint serving the personal allowance, the bands or the NI thresholds, which is why almost every UK payroll project hard-codes them. This dataset exists to fill that gap.

Where do I get UK income tax bands in code?

From data/latest.json for the current tax year, or a pinned file like data/2026-27.json when a calculation has to stay reproducible. Both carry England, Wales and Scotland.

Are the National Insurance thresholds in here too?

Yes — employee thresholds and rates under nationalInsurance.employee, including the category B reduced rate for married women and widows, and employer figures under nationalInsurance.employer.

Does it cover all five student loan plans?

Yes: Plans 1, 2, 4, 5 and Postgraduate, each with its threshold and rate. Plan 5 is the one most libraries are missing — repayments began in April 2026 and its £25,000 threshold is the lowest of all the plans, so a Plan 5 borrower repays more than a Plan 2 borrower on the same salary.

How often is it updated?

Each April, when the new tax year takes effect. The figures are generated from tables whose build fails rather than serve a stale year, so the dataset cannot silently drift. meta.reviewedOn in every file records when it was last checked.

Can I use it in a commercial product?

Yes. CC BY 4.0 — keep the attribution line and you are done.

Licence

CC BY 4.0. Free for commercial use. The attribution line is the only condition:

Data: True Take-Home (https://truetakehome.co.uk)