Who should approve contract labor and staffing invoices

Executive Summary

Contract labor and staffing invoices need two separate approvals, not one. The first is an operational approval: did these people actually work these hours, on this site, on this job. The requesting manager or site supervisor owns that check, because they were there.

The second is a commercial approval: is the bill rate, the markup, and any overtime or shift differential the one the master service agreement specifies. That check belongs to procurement, AP, or a controller with the contract in hand, not to the manager who requested the labor.

The mechanism that causes drift is the separation of these two facts. A supervisor approving on hours worked has no reason to open the rate card, and a rate card review has no visibility into whether the hours were real. When one person signs off on both, at least one of the two checks does not actually happen; it is signed on trust.

The fix is a two-signature workflow: operational sign-off on hours and headcount, commercial sign-off on rate against contract, both required before the invoice is paid. Neither signature substitutes for the other.

1. Who confirms the hours worked?

The site supervisor or hiring manager who requested the contract workers is the only person positioned to confirm hours worked, shift, and headcount. They were on site or reviewing timesheets directly. This approval answers one question only: did the work happen as billed. It says nothing about whether the rate charged for that work is correct.

This approval is fast and should stay fast. A supervisor comparing a timesheet to a staffing invoice is checking dates, names, and hours against a record they already have. Slowing this step down by asking the supervisor to also validate pricing creates a bottleneck and does not actually improve rate accuracy, because the supervisor has no rate card to check against.

The risk in this step, when it goes wrong, is headcount that does not match the roster, or hours billed for a shift that was canceled. Those are operational facts, caught by someone with operational visibility. Keeping this approval narrow is what makes it reliable.

2. Who confirms the bill rate is correct?

A second approver, typically in procurement or accounts payable, checks the bill rate, markup, and any overtime or shift differential against the master service agreement's rate card. This is a document comparison, not a site visit. It requires the current contract on hand, which the requesting manager usually does not have.

Staffing agreements often carry more than one rate: a standard bill rate, an overtime multiplier, a shift differential, and sometimes a rate that steps down after a volume threshold. Each of these can drift independently. A markup written into the signed agreement can show up on an invoice at a different figure with no explanation attached.

See: labor rate deviations against master service agreements for how this specific drift shows up line by line. The approver here needs the contract document itself, not a summary of it, because the deviation is often buried in a line that otherwise looks routine.

3. Why does one approver miss what two approvers catch?

A single approver has to split attention between an operational fact and a commercial one, and only has direct access to one of them. When the requesting manager signs the whole invoice, the rate portion gets approved on trust because that manager has no rate card to check it against. The invoice clears with an unverified number inside it.

This is not a question of diligence. The manager who requested welders for a production run is qualified to say those welders showed up and worked the shift. That manager was never given the master service agreement, was not part of negotiating it, and has no standing reference document to compare the invoice against.

Splitting the approval does not add a step for its own sake. It assigns each check to the person who can actually perform it. A workflow that asks one person to do both checks is asking them to guess at the half they cannot see.

4. What should the approval workflow look like on paper?

A defensible workflow names two required approvals before payment: operational sign-off on hours, headcount, and site, and commercial sign-off on rate against the master service agreement. Both are required, neither substitutes for the other, and the commercial approver holds the current contract, not a memory of the original negotiated terms.

The two-signature structure also creates an audit trail that shows which fact was checked by which person, which matters when a discrepancy surfaces months later and someone needs to know whether it was a hours problem or a rate problem.

1. Operational approval: Site supervisor or requesting manager confirms hours, headcount, and shift against timesheets or site records.
2. Commercial approval: Procurement or AP confirms bill rate, markup, and differentials against the current master service agreement rate card.
3. Escalation on mismatch: Either approver can hold the invoice; a mismatch on either check stops payment until resolved, not just noted.
4. Contract version control: The commercial approver works from the current signed rate card, not an email summary or a prior year's terms.

5. What happens when staffing rates are actually moving?

A rate increase on an invoice is not automatically drift. It is drift only when it exceeds what the contract permits or arrives without the contractual notice or approval the agreement requires. Employment services pricing moves over time, so a higher bill rate on its own is not proof of overbilling; the question is whether the contract's escalation terms cover it.

An approver who sees a higher bill rate than last quarter should not assume overbilling. The relevant question is whether the master service agreement allows for a rate adjustment of that kind, on that schedule, with that notice period. Many staffing agreements include an annual escalation clause tied to a published index; if the contract cites one, the increase should trace to it.

See margin drift vs. legitimate price increases: how to tell them apart for the general method. On a labor invoice specifically, the commercial approver's job is to find the escalation clause, if one exists, and confirm the new rate matches what it permits, not to assume every increase is a mistake or wave every increase through.

6. Where does this approval gap actually cost money?

The cost of a single-approver workflow shows up as a rate charged above the contracted rate card, workers billed who were never part of the approved roster, or overtime multiplied incorrectly. None of these show up as an obviously wrong invoice. Each looks like a normal line item to anyone without the contract open beside it.

A company auditing a year of contract labor invoices after the fact, rather than at approval time, is finding these gaps retrospectively instead of preventing them. See how do you audit contract labor and staffing invoices for the retrospective version of this same check, and what does a contract labor and staffing invoice actually charge for to see the line items a rate approver needs to recognize.

For the wider pattern this sits inside, start with the margin drift guide.

A. Off-contract resources

People are billed who were never added to the agreement's approved roster or job classification, something an hours-focused approver has no reason to flag because the timesheet itself looks correct.

B. Rate card enforcement gaps

Rate card enforcement can fail even when timesheets were approved correctly, because an approved timesheet confirms hours, not price. The two checks answer different questions and neither substitutes for the other.

For the wider pattern this sits inside, start with the margin drift guide. See also accessorial charge audit: the surcharges nobody validates and rate card enforcement: why approved timesheets still produce wrong invoices.

7. Frequently Asked Questions (People Also Ask)

Should the same person ever approve both hours and rate?

No. Combining the checks in one approver means the check that person cannot directly verify gets signed on trust instead of confirmed. Keeping the checks with separate approvers, one operational and one commercial, is what makes both checks real rather than nominal.

What if the requesting manager also has access to the rate card?

Access is not the same as review. The point of splitting the approval is workflow discipline: a named commercial approver whose job is to compare the invoice to the contract, not a manager who could theoretically check but is focused on confirming the work happened.

Does this two-approver process slow down payment?

It adds a step, not a delay, if both approvals run in parallel rather than sequentially. The operational approver can confirm hours the same day the commercial approver checks the rate card, since neither depends on the other's finding.

What documents does the commercial approver need on hand?

The current signed master service agreement with its rate card, including any overtime multiplier, shift differential, and escalation clause. A summary or an email referencing old terms is not sufficient, since the deviation is often in a detail a summary would omit.

How do you handle a staffing vendor with multiple sites and multiple rate cards?

Each site or job classification should map to a specific rate card in the contract, and the commercial approver should confirm the invoice cites the correct one for that site rather than applying one rate blanket across all locations.

What happens if the operational and commercial approvals disagree with each other?

They do not disagree with each other, since they check different facts. A mismatch inside either check, hours that do not match the roster or a rate that does not match the contract, stops payment on its own until resolved.

Who should own this approval workflow, procurement or AP?

Either can hold the commercial approval as long as the role has the current contract on hand and is not the same person who requested the labor. Some companies split it further, with procurement owning the contract relationship and AP executing the line-by-line check.

Is a two-signature workflow needed for every staffing invoice regardless of size?

The mechanism matters more than a dollar threshold: any invoice combining an hours component and a rate component benefits from separating the two checks, since the failure mode, an unverified rate signed on trust, does not depend on invoice size.