Review the official sources PayBreakdown uses for UK tax, National Insurance, student loans, pensions, statutory pay, and financial-promotion guardrails.
This page lists the official sources PayBreakdown checks when maintaining UK salary, tax, National Insurance, student-loan, pension, statutory-pay, childcare, contractor, and financial-promotion assumptions.
| Tax/source year | 2026/27 |
|---|---|
| Region | England/Wales/Northern Ireland |
| Tax code basis | 1257L where the page uses PAYE defaults |
| Pension basis | No pension deduction unless this example says otherwise |
| Student loan basis | No student loan unless selected in this example |
| What is not decided here | PayBreakdown does not decide payroll correctness, lender approval, benefit entitlement or employer compliance, and does not give regulated financial, mortgage, debt, tax, payroll or legal advice. |
|---|
PayBreakdown uses source links to keep calculator assumptions visible. A salary page might use Income Tax, National Insurance, student loan, and pension sources; a childcare page might use Tax-Free Childcare sources; and contractor pages use IR35 and umbrella-company guidance.
Source links do not turn a planning estimate into advice, a payroll decision, a benefit entitlement decision, or a lender decision. They show the public material that informs the assumptions and caveats.
Tax and payroll assumptions should be rechecked when a tax year changes, when GOV.UK publishes new rates, when student-loan thresholds move, when statutory-pay rules change, or when a future calculator phase opens a new source-backed model.
This page supports the calculators by explaining the operating position behind them. Read it alongside the relevant calculator output when you need to understand assumptions, limits, contact options, privacy choices, source checks, advertising separation, or terms of use.
Trust and policy pages explain how PayBreakdown works, but they do not replace official guidance, employer or payroll records, lender documents, legal advice, tax advice, debt advice, financial advice, or a formal data-rights response where one is required.
If this page affects a calculation choice, compare it with the current tax year, source date and methodology notes used by the relevant calculator. If it affects privacy, advertising or data-rights choices, use the named contact option and avoid sending salary details you do not need to share. PayBreakdown holds nothing on a server: calculations run in your browser, and a saved setup stays in that browser only. For important decisions, keep a copy of the relevant calculator result, source date and assumptions so you can compare them with updated guidance later. Recheck this page after major product, advertising or calculation changes.
Every figure records the date it was read from its official page, and those dates are stored alongside the value in shared/taxRuleCitations.js. A build check re-runs the calculation engine against the published figures at each marginal-rate boundary, so a rate that has moved fails the build rather than being noticed later. Rates are re-read at the start of a tax year, and whenever a Budget or statutory-pay uprating changes them.
Third-party summaries go stale quietly and often round or simplify. That matters here because one wrong threshold silently affects every page that uses it — it has happened once on this site, when three of five hard-coded student loan thresholds were wrong. Every figure now lives in one place and is read from GOV.UK or HMRC directly, so a correction is made once and reaches every page that uses it.
Trust the payslip. These pages model standard PAYE with the assumptions each page states; a real payslip can differ because of a non-standard tax code, mid-year changes, salary sacrifice, benefits in kind, or an employer's own payroll timing. The point of showing the assumptions is to let you find which one differs.
Last updated 2026-08-27. Checked by Sean Elsmore. Rates last checked against GOV.UK on 2026-08-07. Estimates are for planning and should be checked against official records where the decision matters.