Agency Invoicing Checklist

Open the job in Workamajig (or Function Point / Advantage) and confirm the SOW is countersigned and dated. Bill against the executed scope, not the verbal scope — invoicing past an unsigned SOW is the most common reason AP kicks an invoice back.

Lock the period in Harvest or the Workamajig timesheet module. Chase any open hours from creative, strategy, and producers before the cutoff — late timesheets entered after invoicing turn into write-offs or awkward corrected invoices.

Reconcile production company, post house, music license, stock, and freelancer invoices against the approved bid. Flag anything billed above the bid line so the producer can resolve before it hits the client invoice. Attach PDFs as backup.

Any out-of-scope work needs a signed CO before it is billed. Verbal approvals from a client lead do not survive AP review at most enterprise clients. If the CO is unsigned, hold that line and bill it next cycle.

Match the line-item format the SOW specified — retainer fee, T&M with rate card and hours, or fixed-fee deliverables. Some clients (especially CPG and pharma) require line-item detail; others (financial services) require a single retainer line. Use the format their AP expects.

Apply the mark-up rate stated in the MSA (commonly 17.65% commission-equivalent, or a flat 10-20% handling fee). Procurement-led MSAs sometimes prohibit mark-up on certain categories — re-read the billing schedule before applying.

Advertising services are taxable in some states (e.g., parts of NY, OH, TX) and exempt in others. Use the client's bill-to address, not the agency's office. Production deliverables may have separate tangible-personal-property treatment from service fees.

Bundle the timesheet detail report, vendor invoices, and any signed change orders into a single PDF appendix. Most enterprise APs require backup at submission; missing backup pushes the invoice into a hold queue and resets the Net-30 clock.

The AD owns the client relationship and must sign off on what gets billed — including which write-offs to absorb and which to push. Capture the decision before sending to finance for the WIP review.

Reopen the draft, apply the requested write-offs or line edits, and re-route to the AD for a final OK. Document the change in the job notes so the next cycle's invoice does not reintroduce the same issue.

Finance reconciles the invoice against the WIP report and confirms the revenue recognition treatment (percentage-of-completion vs. milestone vs. retainer straight-line). Catch over-billing before the invoice goes out — clawbacks are worse than slow billing.

Pull the active PO from the client procurement portal (Coupa, SAP Ariba, Workday) and confirm sufficient remaining balance. Invoices submitted against a closed or exhausted PO are auto-rejected and cannot be appealed without a new PO.

Submit through the client's preferred channel — Coupa / Ariba / Tradeshift portal, AP email inbox, or EDI. Save the submission confirmation; this is the date that starts the Net-30 clock, not the invoice date on the PDF.

Mark the invoice issued in the agency system, update the job's billed-to-date, and store the final PDF and submission confirmation in the client folder. The AD and finance both pull from this record during the next forecast cycle.

Review the AR aging in Workamajig at the 30-day mark. Anything in the 31-60 bucket needs an outreach plan; anything pushing 60+ should be flagged to the AD and managing director before it ages further.

Email the client AP contact with the invoice number, PO number, submission date, and PDF reattached. Copy the day-to-day client contact for visibility but address AP directly — the day-to-day rarely controls payment timing.

If AP has not paid within five business days of the Net-30 nudge, brief the AD with the invoice and PO details and ask them to call the client lead. Finance-to-AP email chains stall at 60+ days; a relationship call from the AD usually unblocks it.

Match the ACH or wire to the open invoice in Workamajig and the GL. Watch for short-pays — clients sometimes deduct a write-off the AD did not approve. Short-pays need a documented decision before closing the invoice.

If this is the final invoice on the job, mark the job closed in Workamajig and archive timesheet detail, vendor invoices, signed COs, and the paid invoice into the client folder. This is the record auditors and procurement reviewers ask for during MSA renewals.