Editorial and accuracy policy

How a number gets onto this site

Every tax figure is read off the document that sets it, not off a summary, a table or another calculator. For federal figures that means IRS Rev. Proc. 2025-32, § 3.01, Tables 1-4; for a state it means that state's own department of revenue publication; for a local rate it means the state's official rate file.

Each figure is stored with three things attached: the document it came from, the URL of that document, and the date it was checked. Those travel with the number into every page that uses it, which is why a state page can tell you what was verified and when rather than asserting a rate.

Where a figure has not yet been read off a primary source it is marked as compiled rather than primary, and the page says so. That distinction is enforced by a test, in both directions: a page cannot claim verification it does not have, and it cannot present an unchecked figure as though nobody had considered it.

So far 37 states have been reviewed: 21 matched the compiled sources and 12 did not. Retirement income rules were checked separately across 34 states, because they are the area where compiled sources fail most often — several states exempt by source rather than by amount, which a single "retirement exclusion" field cannot express.

The verification log is published rather than kept internally, and every entry names the document and the date.

Who writes and who reviews

Content is written and maintained by Pablo Ruiz Quintero, founder. Every page carrying tax content has a byline and a verification date, so there is always a named person responsible for what it says.

There is no panel of credentialed reviewers, and we are not going to invent one. Listing fabricated experts is a specific and common dishonesty in this category, and a site that does it has told you something important about everything else on it.

If a licensed professional — a CPA or an enrolled agent — joins the project, this page is where that will be documented: who they are, what they review, and from what date. Nothing will be retroactively described as reviewed by someone who was not there.

The engine is reviewed differently and arguably more rigorously: every rate has tests behind it, chosen at the points where a rule changes rather than in the middle of a band, because a wrong implementation and a right one agree in the middle and diverge at the edges.

Content is also tested. One test checks that no internal working note appears on an English page, written after a verification log shipped in the wrong language on all 51 state pages. Another measures whether county pages genuinely differ from one another rather than being one template with the numbers swapped.

When figures get updated

Federal figures are refreshed when the IRS publishes the revenue procedure for the coming year, in the autumn before it applies. That is a single document and a single event, and it is the easy half.

State figures are the hard half: 51 jurisdictions, 51 legislative calendars, no common publication date. They are checked on a rolling basis, and each carries its own date rather than a site-wide "last updated" that would be true of only one of them.

Retroactive enactment is the specific hazard. A state passing a rate change in May with effect from 1 January invalidates every table published in the first five months of the year, and nothing about a published table signals that it has been overtaken. This is why we date figures rather than pages.

When a figure changes, the change is recorded in the tax data changelog with the date, the old value, the new value and the source. Calculators affected by it are named.

Nothing is updated silently. A number that changes without a record is indistinguishable from a number that was always wrong.

What happens when we are wrong

It is corrected, and the correction is published with the date and what it affected. Not quietly fixed — published, on the corrections page, where anyone can read what went wrong.

That policy costs something and is worth it. A calculator that has never announced an error is either very new or not looking, and from the outside a reader has no way to distinguish those two unless the log exists.

The errors published so far include publishing one county's property tax rate on another county's page, shipping a verification log in the wrong language across 51 state pages, and coming close to publishing New York City's withholding rates as though they were its statutory rates.

Each entry names what caused it and what now prevents it. Most have a test attached, because a correction without one is a promise rather than a change.

If you find something wrong, the corrections page is the fastest route. We would rather be told than be right, and a report that turns out to be mistaken costs us nothing.

Questions

Who writes the content on this site?

Pablo Ruiz Quintero, founder. Every page carrying tax content has a byline and a verification date. There is no panel of credentialed reviewers, and we do not list one — inventing reviewers is a common dishonesty in this category and we would rather say so.

Is the tax logic reviewed by a professional?

Not currently by a licensed CPA or enrolled agent. It is reviewed against primary sources and covered by tests written at the points where each rule changes. If a licensed professional joins, this page will document who, what they review and from when — with no retroactive claims.

How often is the data updated?

Federal figures when the IRS publishes the annual revenue procedure. State figures on a rolling basis, each carrying its own date rather than a site-wide "last updated" that would be true of only one of them. Every change goes in the tax data changelog.

What do you do when you find an error?

Correct it and publish the correction with the date and what it affected, rather than fixing it quietly. Of 37 states checked against their own department of revenue, 12 carried a wrong figure in the compiled sources — and our own mistakes are on the corrections page alongside them.

How do I report a mistake?

Through the corrections page. A report that turns out to be mistaken costs us nothing, and one that is right is worth considerably more to us than being told the site looks good.