PayStubCheck checks only what can actually be checked from the information supplied. Missing payroll facts are never silently invented merely to produce a result.
Result definitions
The reported amount reconciles with an independent calculation within the check's documented tolerance.
A mathematical discrepancy or unusual relationship exists. The result identifies what differs; it does not label a document fake or fraudulent.
The calculation requires information that was not supplied. PayStubCheck does not create missing W-4, TD1, age/election, taxable-wage, or deduction-treatment facts by assumption.
The calculation falls outside current UCC coverage or the applicable engine module cannot independently determine the amount from the supplied evidence.
Three review layers
- Quick Check: direct gross-to-net arithmetic performed entirely in the browser.
- Detailed Review: browser arithmetic plus supported U.S. and Canadian statutory calculations through PayStubCheck's existing payroll engines.
- Compare Pay Stubs: browser-only YTD continuity across two or three statements, with strong delta equations enabled only when continuity assumptions are confirmed.
Printed YTD direction
Pay stubs generally print YTD values including the current pay period, while several payroll formulas need the value before the current period to enforce annual wage bases and contribution maximums. Where an engine explicitly expects prior-YTD state, PayStubCheck derives it as:
Prior YTD = Printed YTD − Current Period AmountIf that relationship produces an invalid negative value beyond rounding tolerance, the dependent statutory check is not run.
Rounding and tolerance
There is no single universal tolerance. Displayed-value sums, hours × rate calculations, aggregate reconstructed totals, and statutory formulas use different documented tolerances. Exact statutory engines retain their own prescribed rounding rules. A result can therefore be labeled within rounding tolerance without being treated as an unexplained discrepancy.
Ruleset date coverage
UCC V1 statutory calculations currently use approved 2026 U.S. and Canadian payroll rules for pay dates from January 1 through December 31, 2026. Statements outside that window can still receive arithmetic and continuity review, but statutory amounts are marked Not evaluated rather than being calculated with a mismatched year's rules.
Calculation change history: Material changes to rules, caps, source coverage, YTD handling, tolerances, and calculation behavior are recorded in the Payroll Calculation Changelog.
Privacy model
Quick Check and Compare Pay Stubs perform their payroll calculations in the browser. Detailed Review does not require employee identity and sends only calculation evidence needed for requested statutory checks. Payroll figures are not stored as UCC payroll records. Temporary pseudonymous abuse-protection counters may be used for the Detailed Review service.
U.S. payroll calculation coverage
Coverage is generated from the same federal/state source registry and calculation modules used by the review engine. The table translates technical engine metadata into reader-friendly coverage labels while keeping the underlying method available for auditability.
| Jurisdiction | Availability | Calculation approach | Official references | Review date |
|---|---|---|---|---|
| Loading coverage… | ||||
Canadian payroll calculation coverage
Canadian review uses PayStubCheck's existing payroll engine and official-source registry. Québec contribution paths remain distinct: QPP, QPP2, reduced-rate EI, and QPIP are evaluated separately where sufficient evidence is supplied.
| Jurisdiction | Availability | Checks & evidence | Official references | Engine |
|---|---|---|---|---|
| Loading coverage… | ||||
What the coverage labels mean
The calculation follows an official formula, elected rate, or statutory method that can be reproduced directly when the required evidence is supplied.
The calculation is structured from current official withholding tables, formulas, or agency guidance and may depend on jurisdiction-specific inputs.
The jurisdiction does not impose the state-level employee income-tax withholding being reviewed. Other payroll obligations can still apply.
The Canadian calculation path is backed by the versioned PayStubCheck engine and its CRA/Revenu Québec source registry.
Coverage data generated from the active calculation-source registry: loading…
Current limitations
- Calculation consistency is not a document-authenticity determination.
- UCC does not score applicants or recommend approval/denial decisions.
- Unsupported countries and currencies receive arithmetic-only review.
- Canadian federal/provincial income-tax withholding is not independently recalculated unless the complete evidence required by the authoritative formula can be supplied without assumptions; initial UCC V1 may return Unable to determine for those components.
- Special payroll events such as off-cycle checks, corrections, bonuses, and system migrations can legitimately interrupt simple multi-stub YTD continuity.