Corrections Policy

If something on Casvia is wrong — a rate, a threshold, a formula or a guide — we want to know. This page explains how to report an error and how we handle it.

How to report an error

The fastest way to report a problem is by email: [email protected]. To help us investigate, please include:

The page URL (for example https://casvia.uk/income-tax-calculator/).
The inputs you used, if the issue is with a calculator result.
What you expected to see, and what you actually saw.
An official source if you have one (for example a GOV.UK or HMRC page showing the correct rate or threshold).

You can also use the contact page. We read every report.

What happens after you report it

Every error report goes through the same check process:

Triage — we confirm the page and reproduce the issue where possible.
Verification — we check the claim against the official source or an independent calculation. A report is only acted on if the error is confirmed.
Correction — the fix is made and tested (unit tests, golden cases and full-site checks run before anything ships).
Record — material corrections are noted in the page's update history where the page supports it, and in our change log.
Response — where a reply address is available, we confirm what was found and what changed.

How data and formula errors are corrected

Errors fall into two categories, and both are handled with the same discipline:

Data errors — an outdated or incorrect rate, threshold, allowance or tax-year figure. These are corrected by updating the data layer to the official published figure, updating the affected page text, and re-running the tests that reference the value.
Formula errors — a calculation that does not match its stated formula. These are corrected in the calculation logic, with new golden tests added so the same error cannot quietly return.

We never correct a figure by editing the visible result only — the underlying data, logic and tests are updated together so the site stays consistent.

Record of significant revisions

Material corrections and rule changes are recorded in two places:

Page-level — calculator pages display their applicable tax year and last verified date, so a reader can see how current the page is.
Change log — notable corrections (for example a tax rate change) are described in the page's methodology notes and in our Data Sources & Update Policy page, which explains how often rules are reviewed.

Contact

To report an error or ask a question about this policy: [email protected]. We are a small site and aim to reply within a few working days.

Casvia is an educational site and does not provide personal financial, tax or investment advice. Corrections reports are about the accuracy of the site itself, not personal advice requests.