PaycheckSum

Disclaimer — estimates and data status

Last updated: October 26, 2026. This page describes the site as currently built.

1. Estimates only

Every figure on this site is an estimate produced by a documented model. Small differences from your real paycheque are expected: your employer's payroll settings, your elections and your year-to-date amounts all move real figures.

2. Not a payroll service

This site does not file, remit or withhold anything, for anyone, and using it creates no client or advisory relationship.

3. How data status is labelled

Each jurisdiction's parameters carry one of these statuses, shown on the calculator pages and in their data:

  • Primary-verified: checked line by line against the primary source (an IRS publication, a state agency table, the CRA, HMRC).
  • Documented derivation: the figure is derived from a statute rather than published as a table. Arizona's 2026 standard deduction is the current example: Arizona law (A.R.S. §43-1041(H)) sets it equal to the federal standard deduction under IRC §63, published by the IRS in Rev. Proc. 2025-32 — and every Arizona result says so on the result itself.
  • Compilation-checked: parameters compiled from published 2026 tables and cross-checked, but not yet verified line by line against the primary publication. Vermont is the current example: its 2026 standard deduction had not been published by the Vermont Department of Taxes when the data pack was built.
  • Blocked: no figure is shown rather than an unverified one.

4. Known limits that matter

Federal withholding is computed for each pay period with the IRS Pub. 15-T percentage method (Publication 15-T, Worksheet 1A). State income tax is annualized — the engine computes the annual tax and divides by pay frequency — and state per-period withholding tables are not reproduced: a deliberate, documented limit. Pennsylvania municipal earned income taxes and Ohio city/school-district taxes are not modelled in this version and their pages say so. Where a state assigns SUTA rates strictly by industry with no published schedule, the employer calculator shows SUTA as $0.00 with a warning rather than inventing a rate. Workers' compensation figures are estimate ranges, never quotes.

5. Reserve modules

The Canada and United Kingdom pages are samples for modules that are not activated. Each carries its activation conditions on the page; their figures are not offered for reliance.

6. Verify before acting

Each calculator line cites its primary source (IRS, SSA, DOL, state agencies) and its verification date. Verify any figure against that source before acting on it.