Our method
Editorial policy
Trustworthy tax content starts with primary sources, versioned rules, and clear limits on what an estimate can promise.
Primary sources and methodology
Federal withholding methodology references the 2026 IRS Publication 15-T, including Worksheet 1A and its Percentage Method tables. Social Security and Medicare assumptions are checked against applicable Social Security Administration releases and official federal guidance. State explanations are based on official revenue-department publications, statutes, and current tax-year instructions where available.
Annual 2026 tax-engine audit
Before a tax year is treated as current, we review federal thresholds, filing-status behavior, FICA limits, state rates, deductions, and supported pay frequencies. The 2026 audit includes the $184,500 Social Security wage base and checks that federal withholding remains distinct from final annual tax liability. Calculation modules are versioned by jurisdiction and tax year, and deterministic fixtures cover key thresholds and representative inputs.
Review and updates
We monitor primary-source changes and update constants or explanations when an official release changes a material assumption. Each guide should identify its tax year, distinguish an estimate from advice, and link readers to the relevant calculator hub. Unsupported combinations should fail clearly rather than receive an invented rate.
Corrections
If you identify an unclear statement, broken link, or possible source mismatch, use the contact form with the page, claim, tax year, and primary source that prompted the question. We investigate against the relevant official material, correct confirmed errors promptly, and update the page when the correction changes the meaning of the guidance.