Data Sources & Update Log

Last updated: September 10, 2025 See: Methodology

This page lists the sources we rely on and the changes we’ve made to our calculators and guides. Each entry includes the date, what changed, where it applies, and a link to the underlying source where possible. For our editorial standards and QA, see our Editorial & Review Policy.

Where Our Numbers Come From

Federal (Primary)
  • IRS publications & notices (brackets, standard deduction)
  • Social Security wage base, Medicare surtax thresholds
  • Treasury/IRS employer withholding guidance
States (Primary)
  • State Departments of Revenue / Taxation
  • Employer withholding booklets & bulletins
  • Enacted statutes/regulations & official FAQs
Local (Primary)
  • City/municipal and school-district tax pages
  • Local revenue departments, ordinances
  • Official rate tables and residency/workplace rules
Secondary (When Primary Is Ambiguous)
  • State employer examples, technical memos
  • Government newsletters/advisories
  • We avoid tertiary summaries without citations

For how we turn these sources into paycheck estimates, see our Methodology – How We Calculate.

What We Track in the Log

  • Tax rate or bracket updates (Federal, State, Local)
  • Threshold changes (standard deduction, wage base, credits)
  • Logic adjustments (e.g., local applicability, residency vs. workplace rules)
  • Bug fixes & rounding (calculation or display corrections)
  • Content edits that materially affect user understanding (guides, tooltips)

Change Types (Legend)

[TAX] – New rate/bracket/deduction
[LOGIC] – Calculator logic change
[LOCAL] – City/school-district rule
[BUG] – Bug/rounding fix
[COPY] – Content/UX text update

Update Log (Most Recent First)

Date
Type
Change Summary
Applies To
Source
2025-09-10
[LOCAL]
Added NYC resident local tax note and verified rates; clarified residency vs. workplace rule.
City calculators → New York, NY
2025-09-07
[BUG]
Fixed biweekly → annual rounding edge case for 27-pay periods year displays; no change to core tax math.
Internal QA test cases
2025-08-29
[TAX]
Updated Social Security wage base and Medicare surtax thresholds for upcoming tax year placeholders.
Federal calculators (all)
2025-08-15
[STATE] / [LOGIC]
Implemented flat-to-progressive transition for Example State; added state standard deduction handling.
2025-08-01
[COPY]
Refreshed W-4 guidance in Guides; added examples and links to official instructions.

Tip: keep the newest entries at the top. Link “Source” to the official PDF or page when available.

Browse All Calculators

Found an Issue? Help Us Improve

If you notice an outdated rate or a calculation issue, please contact us with:

  • The page URL and your inputs (location, frequency, gross pay, deductions)
  • What you expected vs. what you saw
  • Links or PDFs from official sources (if you have them)

Email: contact@citypaycheckcalculator.com • Contact page: citypaycheckcalculator.com/contact/

Update Cadence & Archive

  • Annual rollovers: Federal/state updates are prioritized at year-end; local mid-year changes are applied as verified.
  • QA & dual review: Material updates undergo second-review and regression checks.
  • Archive: We keep at least 24 months of change history. Older entries may be summarized in an annual digest.

Related Pages