Temp Worker Overtime Across Multiple Assignments: The FLSA Aggregation Rule

A nurse works Monday through Wednesday at one hospital and Thursday through Saturday at another, both placements through your agency. Each facility saw fewer than 40 hours. The nurse worked 52.

Who owes the overtime? In almost every arrangement like this: you, the agency. And if your time tracking treats each assignment as its own little world, you'll find out via a wage claim instead of a payroll report.

This article is general information, not legal advice. Wage-and-hour law has state-level variations and fact-specific outcomes; talk to employment counsel about your situation.

The rule in plain terms

The Fair Labor Standards Act requires overtime pay, time and a half, after 40 hours worked for the same employer in a single workweek. The unit is the employer and the workweek, not the location, the client, or the assignment.

For staffing, the employer in that sentence is typically the agency: it hires, pays, and places the worker. So when one worker covers multiple client assignments in a week, the FLSA sees one employer and one pool of hours. Two assignments of 26 hours each isn't two sub-40 weeks. It's a 52-hour week with 12 hours of overtime.

The U.S. Department of Labor's overtime regulation (29 CFR 778.103) is explicit that hours for the same employer aggregate across unrelated job assignments. Joint-employment questions can also pull the client into responsibility, but that's a reason for clients to care about your compliance, not a way out of it for the agency.

Why agencies get this wrong mechanically

Nobody decides to skip aggregation. Their tooling decides for them:

• Per-site time clocks. Each client site runs its own punch system; no system sees the whole week. The 26+26 worker looks compliant in both.
• Per-assignment spreadsheets. The tab is organized by client, because that's how billing is organized. Overtime gets computed per tab.
• Late approvals hiding totals. One site's hours are approved Tuesday, the other's Friday. Payroll runs on what's approved.
• The blended-rate wrinkle. When the two assignments pay different rates, the overtime premium must be computed on the weighted average regular rate for the week (unless you've properly arranged an alternative in advance). That is a calculation approximately nobody does correctly by hand, every week, at volume.

Each of these is invisible until an audit, a claim, or a worker who did the math.

What correct looks like

1. One record per worker per week, no matter how many placements, sites, or clients touched it.
2. Overtime computed on the aggregate, automatically, with the weighted-average rate, or a per-job overtime rate agreed in advance, applied when rates differ.
3. The billing side needs a plan. Overtime cost belongs in your bill rates and client conversations. A client whose assignment pushed a shared worker past 40 shouldn't be a surprise invoice line you eat.
4. An audit trail. When the question comes, from a client, a worker, or the DOL, you want "here's every hour, every approval, every change" to be an export, not an archaeology project.

This is a core reason generic time clocks under-serve staffing firms: they're built for one employer tracking its own staff, and client approval and billing simply aren't their problem.

Where this bites hardest

• Healthcare staffing. Per-diem and travel workers routinely float across facilities in a week; shift differentials stack on top of the OT math. (How Hire2Hero handles healthcare)
• Light industrial. High volume plus multi-site workers is the classic aggregation miss at scale. (Light industrial features)
• Any firm sharing "reliable" workers across clients. Your best workers are exactly the ones who end up on two assignments in one week.

The takeaway

Cross-assignment overtime isn't an edge case; it's the default behavior of a healthy staffing business that reuses good workers. The fix isn't vigilance. It's tooling where aggregation is the default: one worker, one week, one overtime calculation across everything.

Hire2Hero computes weekly payroll overtime across every assignment and site a worker touches, applies shift differentials, flags minimum-wage violations, and keeps the full audit trail. It's one of the reasons we built timecard-level compliance into the core instead of an add-on.