What Is a Non-PO Invoice? Definition, Approval and Limits

TL;DR: A non-PO invoice is a supplier invoice that arrives with no purchase order behind it, so accounts payable has nothing to match it against. Some spend legitimately runs without a PO (utilities, rent, subscriptions, small purchases under a threshold). Everything else should be cut with a written list of PO exceptions, a dollar threshold and a "no PO, no pay" rule.

A non PO invoice (also called a non purchase order invoice) is a bill from a supplier for goods or services that were bought without a purchase order being raised first. With a PO invoice, accounts payable checks the invoice against the approved PO and the goods receipt before paying. With a non-PO invoice, that approval happened informally or not at all, so AP has to find out after the fact who ordered it, whether it arrived, which budget it belongs to and who can approve payment. That is why non-PO invoices take longer to pay, cause more coding errors and are where billing fraud hides. The fix is not to ban them: it is to decide in advance which spend may skip the PO, and to route everything else through one.

What is the difference between PO and non-PO invoices?

The difference between PO and non-PO invoices is when approval happens and what the invoice can be checked against. A PO invoice refers to a purchase order that a budget owner approved before anything was ordered. A non-PO invoice is approved after the money is already owed.

The matching column is the one that matters. A 3-way match compares the PO, the goods receipt and the invoice, so a wrong price or a short delivery is caught automatically. A non-PO invoice can only be compared with a contract, if there is one, and with what the person who ordered it remembers. For the document basics, see our guide to the purchase order vs invoice.

ERP systems treat the two as different transactions. In SAP, a PO invoice goes through MIRO, which verifies it against the purchase order and goods receipt, while a non-PO vendor invoice is usually posted with FB60 straight to a G/L account. If you do use MIRO without a PO, SAP's own course material notes that you must enter the invoicing party manually on the Details tab and post items to a G/L, material or asset account (SAP Learning).

Why do non-PO invoices matter?

Non-PO invoices matter because they are where AP time, budget overruns and fraud concentrate. Picture a 40-person manufacturer: a supervisor calls a local machine shop for an urgent bracket repair, the shop invoices $1,850 two weeks later, and the invoice lands in a shared inbox. AP does not know who ordered it, which cost center pays, or whether the repair was finished. The invoice sits while AP emails three people, the supplier chases payment, and nobody checked the price against the two other shops that could have done the job.

The numbers that circulate on this are mostly from vendor surveys, so treat them as direction, not precision:

• In an Invocus survey of 178 North American AP professionals, 23% named non-PO invoice processing as one of their biggest pain points (Zycus).
• Zycus cites IOFM research that non-PO invoices make up about 47% of invoices enterprises receive, and Ardent Partners data of 13.9 days to process a non-PO invoice vs 11.4 days for a PO invoice (Zycus).
• The ACFE's 2024 Report to the Nations found billing schemes, the fraud type that uses fake or inflated supplier invoices, in 22% of occupational fraud cases, with a median loss of $100,000 and a typical 18 months before detection (ACFE).
• The FBI's IC3 recorded $3,046,598,558 in business email compromise losses in 2025, up from $2,770,151,146 in 2024 (IC3 2025 report). A fake invoice with changed bank details is far easier to pay when there is no PO to compare it with.

Which purchases legitimately have no PO?

Some spend is legitimately paid without a purchase order because a PO would add paperwork without adding control: the price is fixed by a tariff or contract, the payee cannot be chosen, or the amount is too small to be worth a requisition. Public universities publish these lists, and they are the most useful template a small business can borrow:

• Utilities and telecoms. Florida State University lists water, electric, sewer, gas, refuse, telephone and data services as allowable non-PO payments (FSU Controller). The University of Colorado names public utility payments as the example of when a payment voucher may replace a PO (CU).
• Rent and leases. FSU allows building leases without a PO, with lease administration approval.
• Subscriptions, memberships and licenses. FSU allows subscriptions and renewals with a 1-year limit, membership fees with a justification form, and professional license fees only when legally required.
• Postage, card fees and registrations. Postal services, merchant credit card fees and conference registrations are on the FSU list.
• Legal and professional fees under a signed agreement. FSU requires General Counsel approval for legal services; Arizona State University pays speaker fees with no PO regardless of amount, but only with a signed agreement completed before the service (ASU).
• Small, capped categories. ASU pays freelance writers without a PO at $1,000 or less per article, and interviewee hotel stays under $10,000.

Notice what is not on these lists: raw materials, components, packaging, equipment, IT hardware and most contractor work. Those are purchases where someone chooses a supplier and a price, which is exactly where a PO and a competitive quote earn their keep. ASU makes the line explicit for freight: FedEx and TForce (UPS) are paid directly, "all others require a Purchase Order." Clemson University runs a formal No PO, No Pay policy for everything outside its exceptions.

How are non-PO invoices approved?

A non-PO invoice is approved by the person who owns the budget and can confirm the goods or service were received, not by AP. AP's job is to check the invoice is complete, unique and correctly coded, then route it. A workable flow for a small business has five steps:

1. Log and check the invoice. Supplier name, invoice number, date, amount, remit-to details and a description. Run a duplicate check on supplier, invoice number and amount.
2. Check it against the exception list. If the spend type is on your allowed list (utilities, rent, subscriptions under contract), it follows the light route. If not, it is flagged as an exception.
3. Find the requester and confirm receipt. The person who ordered it confirms what was delivered or which service period was covered. For services there is no goods receipt, so this confirmation is the control. Corpay recommends recording the authorized scope, the billed period, delivery evidence, the amount accepted and the approver's dated decision (Corpay).
4. Approve against the budget and your thresholds. The budget owner approves the amount and the GL coding. Above a set amount, a second approver signs. Use the same tiers as your purchase approval matrix.
5. Release payment and record the exception. AP pays the approved amount and logs why there was no PO, so the next one from the same supplier can be prevented.

Two rules keep this honest. Never create a retroactive PO just to make an exception look like a routine match: label it as an after-the-fact PO or skip it. And if the person who ordered the work is also the only person confirming it, add a second reviewer above your threshold, because one person both buying and accepting is the gap billing schemes use.

Worked example: what is your non-PO invoice rate?

A non-PO invoice rate is the share of invoices that arrive without a purchase order, and splitting it into allowed and avoidable is what tells you where to act. Take a hypothetical 60-person distributor that received 120 supplier invoices in October, 54 of them without a PO.

The headline non-PO rate is 54 / 120 = 45%. That looks alarming, but 38 of those 54 invoices are fine by policy. The number to manage is the avoidable rate: 16 / 120 = 13.3%. If the 16 avoidable invoices averaged $1,400, that is about $22,400 of October spend chosen without a quote, approved after the fact and coded by guesswork. Bring the avoidable rate to 5% or less (6 invoices or fewer a month) and the invoices AP has to chase drop from 16 to 6.

How can a business reduce non-PO invoices?

A business reduces non-PO invoices by making the PO the easiest way to buy and the only way to get paid, with written exceptions for spend where a PO adds nothing.

1. Write the exception list. Start from the university lists above: utilities, rent, telecoms, subscriptions under contract, postage, card fees, registrations, legally required fees. Everything not on the list needs a PO.
2. Set a no-PO threshold. Pick a dollar amount below which no PO is needed, for example $250 or $500, and route those purchases to company cards with receipts. Universities use caps like ASU's $1,000 per article for writers; choose yours from your invoice data, not from someone else's.
3. Announce "no PO, no pay" to suppliers. Tell suppliers that invoices must quote a PO number, and that invoices without one will be returned. Put it on the PO itself and in your supplier onboarding.
4. Make raising a PO take minutes. Most non-PO invoices exist because the PO process was slower than the phone call. A short purchase requisition form, clear approval thresholds and a template cut that gap.
5. Track the avoidable rate monthly. Report it by department and supplier. Repeat offenders are the people or suppliers to train, not AP.
6. Treat every exception as a sourcing signal. An avoidable non-PO invoice usually means nobody compared quotes. That is maverick spending, and it costs more than the AP time.

For the purchases on the "should have had a PO" list, the bottleneck is usually the step before the PO: getting two or three quotes and turning the winner into an order. AuraVMS is RFQ and purchase-order software for small and medium businesses: you send an RFQ, suppliers reply without creating an account, quotes are compared side by side with automatic L1/L2/L3 price ranking, and the winning quote becomes a PO. AuraVMS starts at $4.99/month, billed annually. Try AuraVMS if your avoidable non-PO invoices come from buying in a hurry.

What are the common mistakes with non-PO invoices?

The most common mistake is treating every non-PO invoice as a failure. A utility bill without a PO is normal; forcing a PO onto it adds work without adding control. Other mistakes:

• Backdating POs. Creating a PO after the invoice to pass a match hides the exception you need to measure.
• No receipt check on services. Without a goods receipt, a service invoice needs someone who saw the work to confirm it. "Looks fine" from AP is not that.
• Skipping supplier setup. Non-PO suppliers still need a W-9 on file. For payments made after 2025, the IRS raised the 1099-NEC and 1099-MISC reporting threshold from $600 to $2,000 (IRS), but you still need the payee's TIN to know whether you must report and to avoid backup withholding.
• Changing bank details by email. Any remit-to change on a non-PO invoice should be verified by phone with a known contact before payment.
• Measuring only the total rate. The 45% vs 13.3% example shows why: split allowed from avoidable.

FAQ

What is a non-PO invoice?

A non-PO invoice is a supplier invoice for goods or services bought without a purchase order. Because there is no PO, accounts payable cannot match it to an approved order and must get approval and receipt confirmation from the person who made the purchase after the invoice arrives.

What is the difference between PO and non-PO invoices?

A PO invoice refers to a purchase order approved before the purchase and is matched against that PO and a goods receipt. A non-PO invoice has no prior approval document, so it is approved after the fact by the budget owner and checked only against a contract or the requester's confirmation.

Are non-PO invoices bad?

No. Utilities, rent, subscriptions, postage and small purchases under a threshold are routinely paid without a PO, including by public universities with strict procurement rules. Non-PO invoices are a problem only when they cover spend that should have been quoted and approved first.

How are non-PO invoices approved?

AP logs the invoice and checks for duplicates, then routes it to the requester to confirm receipt and to the budget owner to approve the amount and coding. Above a set dollar threshold a second approver signs, and AP records why there was no PO.

How do I reduce non-PO invoices in a small business?

Write a short list of spend types that may skip a PO, set a dollar threshold for small purchases, tell suppliers invoices must quote a PO number, make raising a PO quick, and track the avoidable non-PO rate by department every month.

What does "no PO, no pay" mean?

It is a policy that supplier invoices without a valid purchase order number are returned unpaid, except for spend on an approved exception list. Clemson University, for example, runs a formal No PO, No Pay policy under South Carolina's procurement code.

Which SAP transaction is used for non-PO invoices?

FB60 is the usual SAP transaction for entering a vendor invoice without a purchase order, posting directly to a G/L account. PO-based invoices go through MIRO, which verifies them against the purchase order and goods receipt.