The AP Approval Checklist Your Invoice Must Pass

An accounts payable clerk spends about ninety seconds on your invoice before deciding whether it goes into the payment run or into a holding pile. They are not reading it. They are matching it against a list. If a required field is missing or a number does not reconcile, the invoice stops moving and nobody tells you for two weeks. Your 30-day invoice quietly becomes a 50-day invoice.

Here is what the person on the other side actually verifies, and how to make sure your invoice clears each check the first time.

The PO number has to be there and has to match

In most companies large enough to have an AP function, no purchase order means no payment. The clerk pulls up the PO in their system, checks that your invoice references it, and confirms the amounts line up. If the PO field on your invoice is blank, the invoice fails before any other check runs.

Two failures are common. The first is a missing number entirely. The second is a number that exists but does not match, either because the PO was raised for a different amount or you billed against a closed PO. Before you send, ask your contact for the PO and confirm the figure you are invoicing does not exceed what the PO authorised. If you are unsure what a valid one looks like, our explanation of what a purchase order is covers the basics, and the PO number format checker will flag an obviously malformed one.

If the invoice already went out without a PO, do not send a corrected PDF. Add the number to the existing invoice so the AP team sees one document, not two. With a link the recipient can edit directly, the buyer adds their own PO number, you get notified, and the amendment is tracked against the current version. That is the fix for the PO added after sending problem that stalls so many invoices.

The bill-to entity and address have to be the legal one

You invoiced "Acme" because that is who you talked to. AP pays "Acme Holdings Ltd", the registered entity that owns the budget, at a different address. The two do not match, so the invoice sits in exception handling until someone reconciles the name.

The billing entity, the billing address, and the tax registration on the invoice all have to be the buyer's official details, not the trading name on the door. This is where most wrong billing detail problems begin. The safest approach is to let the buyer confirm their own entity and address rather than guessing. When they can correct the bill-to fields themselves, you stop trading emails about which subsidiary to name.

The math has to reconcile to the penny

AP re-adds your invoice. Line items, subtotal, tax, discount, total. If the total does not equal the sum of the parts, the invoice is wrong on its face and gets bounced regardless of whether the intended amount was correct.

Check three things. The line items sum to the subtotal. The tax is calculated on the correct base and at the right rate. The final total matches what the buyer expects to see, including any agreed discount. A rounding difference of a few cents is enough to trigger a hold at a strict AP desk. If tax is involved, run the numbers through the sales tax and VAT calculator rather than doing it in your head.

The tax and legal fields have to be complete

What counts as complete depends on where the buyer is. A UK buyer's AP team expects a VAT number and VAT breakdown on anything treated as a tax invoice. A US buyer may hold payment until you supply a W-9. Cross-border, the reverse-charge treatment has to be stated correctly or the buyer's own tax filing breaks.

Do not send a domestic-format invoice to an overseas client and hope. Check the invoice requirements by country for their jurisdiction and include the identifiers their finance team is required to record. Missing tax fields are one of the quiet reasons accounts payable keeps rejecting an invoice without ever spelling out why.

The invoice number and dates have to be clean

AP systems reject duplicate invoice numbers automatically. If you reused a number, or your numbering has gaps that trip their duplicate-detection logic, the invoice never reaches a human. The issue date and payment terms also have to be consistent: an invoice dated last month with Net 30 terms is already showing as overdue in their aging report, which changes how it gets handled.

Use a sequential, unique number on every invoice and state the terms in plain form, for example "Net 30, due 14 March". If your numbering has grown messy, our numbering system guide shows how to fix it without breaking your books.

Route it to the right inbox

An invoice sent to your day-to-day contact often dies there. Their job is not to pay you; they forward it, or they forget. AP wants invoices in their intake channel, whether that is an email alias or a vendor portal.

Ask who processes payment and get the invoice there directly. If the buyer needs to hand it off internally, make that a single step: our note on forwarding an invoice to accounts payable covers the mechanics, and a shared link lets the buyer add their AP contact and route it without re-attaching anything.

Run your own pre-send pass

Every check above is something you can verify before the invoice leaves your desk. Walk the full accounts payable invoice approval checklist against each invoice, then send. When you create an invoice as a shared link, the buyer confirms their PO, entity, and AP contact on the same document you sent, and approves it in place, which removes most of the reasons an invoice ends up on hold in the first place.