Corrections and editorial policy

On a site whose entire value is being right, errors are treated as incidents, not embarrassments. This page says how figures get onto the site, what happens when one is wrong, and how to tell us.

How figures are published

Every statutory figure is verified against its primary source. HMRC, gov.scot, NHS Employers, the ONS, before it enters the codebase, and lives in a data module that records the source URL and the date it was checked. An automated test suite then gates every build: known anchor calculations must reproduce to the penny, thresholds must reconcile with each other, and the build fails outright if no rate table covers today's date. Prose figures are computed by the same engine as the calculators, so the text cannot silently disagree with the tools.

When something is wrong

• Factual or calculation errors are fixed at source (the data module or engine), which corrects every page that uses the figure at once. The page's checked date updates with the fix.
• Material errors: anything that could have changed a financial decision, get a visible note on the affected page describing what was wrong and when it was corrected.
• If a figure here disagrees with HMRC, HMRC is right: that principle outranks anything written on this site.

Report an error

Use the contact page. Reports about wrong figures are the most valuable mail this site receives; they are checked against the primary source and answered. The full calculation method, anchors and their sources are on the about page.

Editorial standards

No content is sponsored; nothing is sold or affiliated. Statutory figures always carry their tax year and checked date. Where a figure cannot be verified against a primary source, it is not published, pages state what they deliberately don't model rather than guessing. Uncertain or scenario-based numbers (like the fiscal-drag counterfactual) are labelled as scenarios with editable assumptions.

Policy reviewed 2026-08-28, alongside the 2026/27 rate set.