About AX Calculators.

Who runs AX Calculators?

Why does this site exist?

It brings together the conditions that trigger a Self Assessment return and the practical next steps. The purpose is to make the decision traceable: a result has a reason, and that reason has a source.

Registration, deadline, penalty and error pages support that decision. Tax code tools and tax amount calculators are not available in this release.

Where does the information come from?

Tax rules are checked against specific GOV.UK pages and rewritten around the question a visitor needs answered. Published numbers are recorded in the source-linked tax data file, with check dates.

Read our checking method and limitations. Read our one-off original observation record. The method does not establish an individual tax position or a qualification for the site’s operator.

What happens to checker answers?

The checker works inside the browser. Its choices are not uploaded, stored or put into a result URL. This site has no accounts, contact form, newsletter signup or tracking script. A visit still involves normal requests to the hosting provider for page files.

The contact email opens your own email application. Please do not send tax records, identifiers or account sign-in details.