The Act defines “employ” to include “suffer or permit to work” (§ 785.6; “§” is shorthand for “section” — these citations refer to 29 CFR (Code of Federal Regulations) Part 785, the Department of Labor’s regulation on hours worked). That phrase is what makes an employer’s wage bill run on more than the hours the employer scheduled. As Chapter 1 covered, the Act’s § 7 overtime premium runs against actual hours worked — and the courts have read “hours worked” broadly. The Supreme Court first held that employees must be paid for time spent in “physical or mental exertion… controlled or required by the employer and pursued necessarily and primarily for the benefit of the employer.” The Court then went further still: there need be no exertion at all, since an employer may hire “readiness to serve” itself — the employee’s availability to work — and idleness in a standby capacity can be time worked (§ 785.7). The workweek ordinarily includes all the time an employee is necessarily required to be on the employer’s premises, on duty, or at a prescribed work place.

That reach is what separates “suffer or permit” from an agreement about pay. Work the employer never requested is still work time once the employer suffers or permits it — an employee who stays past quitting time to finish an assigned task, correct errors, or complete paperwork is working, and “the reason is immaterial” (§ 785.11). What matters is only whether the employer knew, or had reason to believe, the work was happening. This rule cannot be waived by contract: it holds “even though there may be a custom, contract, or agreement not to pay for the time so spent” (§ 785.8). Two statutory exceptions apply, though. Certain travel, walking, and other preliminary or postliminary activities — occurring before the start or after the end of the employee’s workday — are excluded from working time under the Portal-to-Portal Act, the federal law governing which such activities are compensable, unless the activity is made compensable by contract, custom, or practice. Where an activity is made compensable that way, the Portal-to-Portal Act pulls it back into hours worked: “such time must also be counted” — limited to the amount of time the contract or custom allows, even if the activity actually takes longer (§ 785.9). And a collective-bargaining agreement (an agreement between an employer and a union representing its employees) may exclude clothes-changing and washing time under the § 3(o) exception (§ 785.26). Outside those specific carve-outs, a handbook clause or a standing office norm that off-clock work goes unpaid carries no weight against the rule.

That leaves an employer only one way to avoid paying for unwanted work: actually stop it. Management’s duty is to “exercise its control and see that the work is not performed if it does not want it to be performed” — it cannot “sit back and accept the benefits without compensating for them” (§ 785.13). Critically, a written policy against unauthorized overtime is not, by itself, a defense: § 785.13 is explicit that posting such a rule is not enough on its own — management has the power to enforce it and must make every effort to do so. A policy that exists on paper but goes unenforced in practice, where supervisors watch the prohibited work happen and say nothing, leaves the employer liable exactly as if no policy existed at all.