Editorial policy

Sourcing

Every rate, bracket, threshold and withholding rule on the site comes from a primary source: a statute or code section, a tax agency’s rate table, withholding guide or instructions, an IRS revenue procedure or form instruction, or a state lottery’s own claim page. Third-party summaries, tax blogs and other calculators may help us find a document; they are never cited as the source of a number. Each state page lists the documents it relies on, and the sources page lists all of them with what each one supplies.

When a figure is not published

If we cannot verify a number from a primary source, we do not estimate it. Instead the calculator does one of three things and says which: asks you for the figure (local tax rates, 2027 rates), applies a verified top rate as a labeled upper bound (four states whose indexed 2026 thresholds were not retrievable), or shows the item as “not published” (some lotteries’ state withholding rates). A rule that we inferred — for example, that a selling state taxes a nonresident’s prize as in-state income — is flagged on the result.

Verification cadence

• Every figure was checked against its source on the date shown on each page.
• Federal brackets are re-verified when the IRS publishes the next year’s revenue procedure, normally in October or November.
• State rates are re-verified each December and January, when most states publish next-year tables, and whenever a state enacts a change.
• Lottery withholding rules are rechecked each quarter.
• An automated test fails 45 days before any rule window ends without a verified successor, so updates cannot be forgotten.

The visible “verified” date on a page changes only when its content changes.

Corrections

Anyone can report an error through the corrections form; every page links to it. We read every report, check it against the primary source, and if we were wrong we fix the figure, update the verified date and keep a note of the change in the site’s version history. If the report is right but the source has not yet changed, we say so on the affected page. We do not reply to every report, but a reply address lets us ask follow-up questions.

Use of automation and AI

This site is built and maintained with the help of software tools, including AI assistants, which draft text, fetch documents and write code. Automation never decides a number. Every figure is read from its source document, every calculation is checked by unit tests whose expected values are worked by hand from the source, and every page is built from the same tested engine. Text is reviewed for accuracy against the cited documents before publication.

Independence

No lottery, tax preparer, lender or financial adviser pays us or reviews our content. We carry no advertising and no affiliate links.