The calculators are only useful if their numbers are right, so we treat an error as a priority. This page says what we do about one.
How we check an error
We check a possible error against the official source behind the figure: the data file the calculator reads, or the publication the page cites (all listed on the data sources page).
A confirmed error is fixed within a few days of confirming it. If the fix changes an engine rule or a data file, it also gets a test against the publisher’s own figure before it goes live, so the same mistake can’t come back unnoticed.
How a correction is shown
- The page’s “Updated” date changes to the day of the correction. Dates change only for real changes, never to make a page look fresh.
- The change is listed in the page’s update note, in plain words: what was wrong, what it is now, and the date.
- When an official source publishes a new edition, such as next year’s IRS limits, we add a new dated data file rather than editing the old one, so earlier results can still be traced to the figures they used.
Typos and wording changes that don’t affect any number or rule are fixed without a note.