US Internal Revenue Code Section 3402 Income Tax Withholding at Source (26 USC 3402) 3402e-included-excluded-wages: Apply the half-period rule: treat all or none of a payroll period's remuneration as wages depending on whether more than half the services were wages

What does 3402e-included-excluded-wages require?

For a payroll period of at most thirty-one consecutive days, if the remuneration for services performed during half or more of the period constitutes wages, all remuneration for the period is wages; if the remuneration for services during more than half the period is not wages, none of it is. Employers with workers moving between covered and excluded work in a period (for example agricultural and non-agricultural labour) apply the test to each period.