Getting Paid by Big Companies: Surviving the AP Process

Your invoice to a big company doesn't go to the person who hired you. It goes into an accounts payable system, gets matched against a purchase order, waits its turn in an approval chain, then sits until the next scheduled payment run. Nobody is ignoring you. You're in a queue you can't see, and the queue has rules. Learn them and net 45 stops being a shock; ignore them and even a friendly client can't get you paid.

Vendor Onboarding Comes First

Before a large company can pay invoice number one, you have to exist in their system as a vendor. That means paperwork: a W-9 so they can report what they pay you, your banking details for transfers, sometimes proof of insurance, and increasingly a registration in whatever procurement portal they run. None of it is optional and none of it is fast. Start the day you sign, not the day you invoice, because every week onboarding drags is a week added to your first payment. A vendor record with a name that doesn't exactly match the name on your invoice will also stall things, so decide what your business is called and use it identically everywhere.

The PO Number Is Your Ticket

Most enterprises run some version of a no PO, no pay policy. Your contact requests a purchase order, the budget owner approves it, and the resulting PO number is what authorizes AP to pay you. Get that number before you start work, and print it in its own labeled field on every related invoice. An invoice without one drops into a manual exception queue, which is the AP equivalent of the junk drawer. The distinction between their number and yours is covered in invoice numbers vs. PO numbers.

How Approval Actually Flows

1. 1Your invoice arrives by email or portal and gets scanned into the AP system.
2. 2Software matches it to the PO: vendor name, PO number, amount.
3. 3Someone confirms the work was received, often your day to day contact clicking an approval.
4. 4Any mismatch in name, amount, or PO number diverts it to a human exception queue.
5. 5Once matched and approved, the invoice is scheduled for a payment run based on its terms.

The takeaway: most big company payment delays are self inflicted mismatches. Wrong entity name, missing PO, an amount $200 over the PO because scope grew and nobody amended it. Each is fixable before you send, and nearly impossible to fix quickly after.

Payment Runs and Cutoff Dates

AP departments don't pay invoices as they're approved; they pay in batches, typically weekly or twice a month. Your invoice gets a due date based on its terms, and it's paid in the first run after that date. Miss a run's cutoff by a day and you wait for the next one. This is why an invoice on net 30 terms so often pays in 35 or 40 days: the clock usually starts when they receive and register the invoice, not when you wrote it, and then the run schedule rounds everything up. Ask AP for the run schedule and cutoff day. It's not secret, and knowing it turns your cash flow from guesswork into arithmetic.

The Net 45 to Net 60 Reality

Large companies standardize payment terms across thousands of vendors, and the standard keeps drifting longer. Net 45 and net 60 are now common defaults, and your contract likely accepted them whether you noticed or not. Your negotiating window is during onboarding, before the vendor record is created; afterward the terms are baked in. If you can't move the terms, you have two honest options: price the wait into your rate, or take the company's early payment program if it offers one, trading a percent or two for money now. The math on that trade is laid out in early payment discounts explained.

Chasing Without Burning the Relationship

Status questions go to AP, not to the person who hired you. Email with your vendor name, invoice number, PO number, and amount, and ask two precise things: has the invoice been approved, and which payment run is it scheduled for? Precise questions get precise answers. Bring your day to day contact in only when something is genuinely stuck, like an approval sitting in their own queue. Save the firm escalation for invoices that blow past terms, and keep a paper trail throughout, because with big companies the paper trail is the relationship.