Last updated: 7 October 2026.

Source priority

For jurisdiction-specific tax and invoice claims, we prefer current legislation, regulations and tax-authority material. Where a rule has exceptions or a page is a plain-language guide, the wording and linked source should make that scope clear. A secondary overview is not used as a substitute for an appropriate primary authority when a material claim needs one.

How a source check is recorded

  1. Identify the specific sentence, interface field or calculation behavior that needs checking.
  2. Open an official source that addresses that topic and jurisdiction; avoid linking a generic authority homepage to an unrelated claim.
  3. Check the source’s relevant section, date or amendment note where available, and record limitations that affect the claim.
  4. Keep the source link and review date with the content; display “Last Reviewed” only after the check is complete.
  5. Reword or remove a claim if the source is ambiguous, unavailable or does not support it.

What this review does not do

A source check is not an audit of a user’s invoice or a determination of tax registration, rates, liability, enforceability or legal sufficiency. Country modes and calculators do not infer obligations. Numeric tax rates remain user-controlled: the central registry supplies verified official figures only as suggestions, applied after the user confirms them.

See the actual references and their scope on Sources & Methodology. Report a possible factual error through the Corrections Policy.