Editorial & source policy

Primary-source first

We use official GOV.UK and HMRC guidance as the primary source for published rates, thresholds and allowances. Calculator pages and current guides link to the sources relevant to their calculations.

Who is accountable

Mehmood Rajoka, founder and publisher, is accountable for product direction, source-review standards and correction handling. He is not presented as a chartered accountant, regulated tax adviser or HMRC representative. Rate and threshold claims are checked against the linked official sources and receive a visible review date when that check is completed.

Review and update process

When a new tax year or a relevant official change is published, we review the affected configuration, calculator copy, guide content, metadata and structured data together. Current guides display a review date; older tax-year guides are labelled as historical rather than presented as current.

1. Identify the primary HMRC, GOV.UK or Scottish Government source and record the applicable period.
2. Update the shared configuration or dedicated calculation engine without copying figures into unrelated components.
3. Add or update regression tests at thresholds, band boundaries, zero values and representative scenarios.
4. Review visible assumptions, methodology, metadata, structured data, sitemap entries and AI-readable summaries together.
5. Run the complete test, lint and production-build gate before deployment, then verify the live canonical page and error logs.

How we handle uncertainty

Tax rules contain elections, reliefs and fact-dependent definitions that a short browser calculator cannot decide. We state the supported case, reject unsupported inputs where possible, and show exclusions next to the calculation. We do not turn a missing fact into a favourable assumption or describe an annual planning estimate as an exact payslip.

Where official sources do not yet provide a final rate for a future period, we do not invent one. Review dates describe when the cited source and implementation were checked; they do not imply external endorsement.

Scope and independence

taxcalculators.uk is an independent information service, not HMRC and not a tax-advice firm. We do not claim that a calculator result is a personalised tax calculation. The methodology explains the assumptions and exclusions for each tool.

Corrections

If you spot a factual error, outdated rate, broken calculation or unclear assumption, email [email protected] with the page URL and supporting official source where possible. We investigate substantiated reports and update affected pages when a correction is needed.

Last reviewed

14 August 2026.