This site estimates tax. That only means anything if you can tell where each figure came from and what it does not cover, so both are published rather than assumed.
Every figure comes from a primary source
A tax rate, bracket, standard deduction, exemption or credit is taken from the agency that publishes it — the IRS, a state revenue department, a state legislature, or a municipality — and recorded with the URL and the date it was read. Never from a summary, a competitor, an article, or memory.
The reason is specific rather than decorative. A stale federal standard deduction was once carried into three separate state models here, because each had been copied from the one before instead of traced back to the source. Copying is how a single wrong number becomes several.
Amounts are sourced separately from brackets
A state can use one filing status’s bracket schedule with a different status’s standard deduction, publish its own third deduction, or allow one personal exemption where the federal return allows two. So the brackets, the deduction, the exemption and any credit are each sourced on their own. Inferring one from another is the mistake this rule exists to prevent.
A jurisdiction publishes only when two conditions hold
A state appears on the site when its own figures are verified against official material and every local tax inside it is verified too. A correct state table is not sufficient if a city inside that state carries an unverified rate — the reader would get a confident total built on an unchecked component.
Where a jurisdiction is not ready, it is withheld rather than shipped with a caveat.
Gaps are disclosed, not hidden
No model covers everything. Where a rule is approximated, unmodelled or out of scope, the calculator says so on the page where the figure appears — in the state’s “what this estimate excludes” list, or beside the number itself. The methodology page collects the site-wide ones.
The standard applied is that a reader should never have to discover a limitation by being wrong about their own pay.
What is deliberately not built
This is a paycheck estimator, not a tax return. Some things are refused on purpose because modelling them badly is worse than naming them: multi-state return reconciliation, credits claimed on a return rather than withheld from pay, and the pass-through entity tax election, among others. Each refusal is recorded with its reasoning rather than left as an absence.
The site also does not score or grade your tax position. It reports figures you can check against your own paystub or return; a rating out of a hundred would be a judgement it cannot defend.
Review and correction
Figures are re-checked against their sources on a schedule and whenever an agency publishes a revision — state rates are typically finalised late in the calendar year, so a figure read in August may be superseded in December. Each page carries the date its data was last reviewed.
When something is found to be wrong it is corrected at the source and the correction is recorded, including where an earlier version of this site’s own documentation was mistaken. Corrections here have run in both directions: figures once described as stale turned out to be current, and a disclosure once named the wrong filing status for two months before a test caught it.
Those corrections are published rather than described. The corrections log names each one: the jurisdiction, what the figure said, what it says now, and how the error was found — including one still flagged as unresolved rather than quietly dropped.
Not advice
Everything here is an educational estimate. It is not tax, legal, accounting or financial advice, it creates no professional relationship, and it is not a substitute for a return prepared by someone who knows your circumstances. See the terms and disclaimers.
Telling us something is wrong
If a figure looks wrong, say so: contact@paycheckbase.com. A message naming the jurisdiction and the figure is the most useful kind, and a source is better still. Reports are read on a best-effort basis; this is not a support line for individual tax situations.