Primary sources first
We take tariff and rate data from primary documents — SERC tariff orders, government scheme guidelines and the Finance Act — not from other calculators. Where we temporarily rely on a secondary reference, we label the figure as pending primary cross-check and prioritise verifying it.
Verify before publish
A tariff is not published until it passes our schema validation and has a recorded source and verification status. See our methodology for the exact mechanism.
Label uncertainty honestly
If a number is provisional, or a bill component is not modelled, we say so on the page. We would rather show a clearly-labelled estimate than a precise-looking figure that is wrong.
Corrections
If you find an error, email corrections@desimetrics.com. We review reports promptly, fix confirmed errors, and update the affected calculator's last-verified date so the change is visible.
Independence from revenue
Advertising and affiliate income never influence a calculation, a recommendation, or how a product is ranked. Commercial content is clearly labelled and kept separate from the tools. See our affiliate disclosure.
Last updated: 29 August 2026