FA-59187 / Payroll withholding rules / Member archive

Cumulative wages withholding method: tax to date proration · case 02

Withholding collapses to a single period's share of tax despite prior withholding being subtracted.

Member previewVariant 2 · 3 implementations · 8 checks per implementation

Case contract

Input {ytd_wages, ytd_wh, wage, period_index k (1-based, includes this period), periods}. Annualized = (ytd_wages + wage)*periods/k exactly. Annual tax: 0% to 10,000.00, 12% to 40,000.00, 24% above. Tax to date = annual tax * k/periods. Withholding = max(0, tax_to_date - ytd_wh) rounded half-up at the end.

Why this case matters

The cumulative method spreads irregular pay across elapsed periods and trues up against prior withholding.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
regression 0	`0`	`1684840`	Failed

MEMBER ARCHIVE

The complete case is available to members.

This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

Member access is invitation-based. Sign in with your invited account to inspect the sources.