Build the invoice out of the timesheet, not out of your own totals
- Each worker by name, with the assignment or requisition they were placed on
- The week ending date, matching the client's pay period rather than your billing cycle
- Regular and overtime hours as separate quantities, never as one blended figure
- The purchase order or requisition number their accounts system will refuse the invoice without
- The approver's name, where the agreement puts sign-off with a named manager
The person approving it is holding signed timesheets and comparing line to line. Anything they cannot match in a few seconds — a worker billed under a nickname, two assignments merged into one line, a week that runs Monday to Sunday against their Sunday to Saturday — is not a dispute, but it is a delay, and delays on weekly billing compound faster than they do anywhere else.
The bill rate is on the invoice; the pay rate is not
Almost every client contracts on a bill rate, which means the rate itself is the thing they agreed to and the thing the invoice has to state. Show the rate and the hours and let the total follow from them, because an invoice that states only a total is asking to be trusted about the two numbers underneath it.
Overtime is the line that gets invoices held
An overtime bill rate applied inside a total the client reads as straight time is the single most common reason a staffing invoice sits unpaid. Their timesheet already splits the hours; the invoice that splits them the same way is approved, and the one that does not gets returned with a question that takes three days to answer.
A conversion fee is a one-off against an ongoing relationship
When a client hires a worker directly, the fee usually tapers with the hours already billed on that assignment — the longer they used the worker through you, the less it costs to keep them. Put it on its own line naming the worker and the taper it was calculated under, because it is the one figure on a weekly invoice that nobody was expecting.
If you are the contractor invoicing the agency, this is a different document
Contractors placed through an agency usually bill the agency rather than the end client, often against a self-billing arrangement in which the agency raises the document and you only approve it. Where you do raise it, the counterparty is the agency, the reference is their assignment number rather than the client's purchase order, and the payment terms are the agency's — commonly longer, because they are waiting to be paid themselves.
Common questions
- Should I invoice weekly or monthly?
- Weekly, against the same week the timesheets close. Staffing is one of the few things billed for work already delivered by people who have already been paid for it, so a monthly cycle finances four weeks of somebody else's payroll out of your own cash.
- The client's timesheet and mine disagree. What do I send?
- The hours you can evidence, with the disputed hours held off the invoice rather than argued on it. An invoice carrying a contested line is an invoice nobody approves; one carrying the agreed hours gets paid while the remainder is settled on its own.
- What happens when an assignment ends mid-week?
- Bill the part-week on its own line with the dates it covers, rather than folding it into a full week's line. The client's own records close the assignment on that date, and a line claiming a full week against a worker who left on Wednesday is the kind of error that gets every other line on the invoice re-checked.