Accuracy and accountability
Corrections Policy
How to report a calculation, source, wording, accessibility, or technical problem and how verified corrections are handled.
How to report an issue
Email contact@checkmatter.com with the page URL, exact inputs, result shown, expected result, browser/device, and any supporting authoritative source. Do not include sensitive personal or financial data.
How we investigate
We reproduce the issue, compare the engine with the displayed formula and source, test nearby and boundary cases, and determine whether the problem affects calculation, explanation, metadata, schema, links, or accessibility.
Correction and disclosure
Verified errors are corrected as soon as practical. Material changes to a formula, assumption, source interpretation, or result receive a new reviewed date on the affected page. Minor spelling, formatting, or non-substantive accessibility fixes may be made without a separate change note.
We do not suppress a verified correction because a page contains advertising or an affiliate link.
Corrections policy reviewed: 1 September 2026.