AP automation for manufacturers and distributors: match every line to what arrived

Manufacturing AP automation is software that reads each supplier invoice line by line before it's paid. It matches every line to the purchase order and to the record of what arrived. Only the lines that don't agree go to a person. It helps manufacturers and distributors most, because their invoices are long and their goods often come in more than one delivery.

Why supplier invoices are harder to match in manufacturing#

Much of what a plant buys is ordered on a purchase order (PO) and arrives by truck at the receiving dock. So each supplier invoice has to agree with two other records before it's paid. One is the PO. The other is the record of what arrived, such as a signed packing slip. Checking the three documents against each other is called a 3-way match. The rules behind it are in 2-way vs 3-way matching.

The invoices are long, too. An invoice for fasteners or packaging can list dozens of items, and its table of items can continue over several pages. Before any match, someone has to type in or check every line. One wrong quantity on page 3 can put the whole invoice on hold.

Then the goods don't always arrive the way they were ordered. One PO line may come in two deliveries. The supplier may add freight or a fuel surcharge that the PO never had. The PO may count single units while the supplier bills by the case and the dock counts pallets. Each of these makes an exact match fail, even when the supplier delivered and billed correctly.

An invoice that fails the match is called an exception, and a person has to check it. Exceptions are common. Ardent Partners' State of ePayables 2025, a sponsored analyst report, puts the average invoice exception rate at 18.4%. That's nearly one invoice in five. The same report gives an average cost of $9.84 to process one invoice. These are Ardent's averages for all the organizations it studied, not for manufacturers alone.

One missing pallet, step by step through the match#

Oakline Office Supply, a distributor, ordered paper from Northgate Paper Co. on PO 55821. The order was 168 cartons of copy paper and 48 cartons of cardstock, 216 cartons in all. Northgate shipped 9 pallets with a carrier, Blue Ridge Freight Lines. This is the delivery receipt that Oakline's receiver signed at the dock on September 17, 2026.

The receiver, M. Alvarez, counted 8 pallets with the driver and wrote the shortage by hand. Then Northgate's invoice arrives in the AP inbox. It bills all 216 cartons against PO 55821.

The 2-way match compares the invoice with the PO. It passes, because both show 216 cartons. The 3-way match needs one more step. The receipt counts pallets and the invoice bills cartons, so the match has to turn pallets into cartons first. This load carries 24 cartons on each pallet, so 8 pallets carry 192 cartons. The invoice bills 24 cartons that didn't arrive.

The last row needs a person. The receipt shows that a pallet is missing, but not whether it carried copy paper or cardstock. The receiving team can say which one. The buyer then decides whether to ask Northgate for a credit or file a claim with the carrier. Until then, the invoice waits with the reason attached.

Five exceptions that stop a manufacturer's invoices#

The missing pallet is one kind of exception. AP teams at plants and warehouses see these five as well.

• Split deliveries

  One PO line can arrive in two or three deliveries. The supplier may bill each delivery, or bill the whole line after the first one. The invoice has to be matched to the receipts that exist so far.

• Units that don't agree

  The PO may order single units, while the supplier bills by the case and the dock counts pallets. The quantities agree only after a conversion, and each supplier packs its goods differently.

• Lines the PO never had

  Freight and surcharges often appear only on the invoice. Nothing on the PO matches them, so they need a rule of their own.

• Prices that changed

  A blanket PO covers many deliveries over several months at one price. If the supplier raises its price, the buyer has to accept the new price or ask the supplier to bill the agreed one.

• Invoices ahead of the receipt

  An invoice can reach AP the day the goods ship, days before the receiving team records the receipt. The match should wait for the receipt instead of failing at once.

Set the match rules to fit how your dock receives goods#

Software applies your match rules the same way to every invoice. So write the rules down before you automate matching. An ERP is the business software that holds your orders and accounts. ERP systems let you set these rules in detail. A price tolerance is how much the invoice price may differ from the PO price before the match fails. Microsoft Dynamics 365, for example, lets you set a price tolerance for an item, item group, vendor or vendor group.

• Tolerances by item or vendorIf you use the same tolerance for all purchases, it allows too much difference on costly parts and too little on cheap supplies. Set a percentage limit and a maximum amount together, so a small percentage of a large invoice can't lead to a large overpayment.
• A rule for chargesDecide which freight and surcharge lines can pass without a PO line, and up to what amount. Send the rest to the buyer.
• A conversion for each supplier's unitsRecord how many units are in a case and how many cases are on a pallet, for each supplier and item. The match then compares the same units.
• A rule for partial receiptsDecide whether to pay for what arrived and hold back the rest, or put the whole invoice on hold until the order is complete.
• An owner for each exceptionSend missing quantities to the receiving team and price differences to the buyer. Invoices with no PO go to the person who ordered the goods.
• Approval routes by plantRoute invoices by plant or cost center, so each invoice goes to an approver who understands that purchase.

Our take. The match rules should follow the way your own dock receives goods, not a software vendor's default settings. A plant that weighs steel coil on arrival needs different rules from a distributor that counts cartons. So write down the rules your team already follows, and have the software apply them. If a tool only runs the match rules it comes with, your team ends up rechecking the results in a spreadsheet.

What processing these invoices costs#

Before you compare tools, work out what your invoices cost to process today. The calculator starts from Ardent Partners' 2025 averages, which are $9.84 per invoice and an 18.4% exception rate. Replace them with your own numbers.

The calculator works out the cost with automation in two parts. Each exception still costs what one invoice costs you today. Invoices that match add no cost beyond the software's monthly fee. So the lower your exception rate, the bigger the difference. If split deliveries and different units are common at your plant, your rate may be higher than the average, so enter your own.

Where Docsumo fits, and where it stops#

Docsumo, our product, is an intelligent document processing (IDP) platform. It reads supplier invoices, purchase orders, delivery receipts and bills of lading. It reads handwritten counts and notes as well as printed text. When a table of items continues onto the next page, Docsumo joins the parts into one table. It also maps each column heading to the right data field, such as quantity or unit price.

On the Enterprise plan, Docsumo's cross-document checks match each invoice line to the PO and to the receipt or delivery slip. The checks compare quantity, unit price and amount, so they can do both 2-way and 3-way matching. The Enterprise plan also includes master data lookup. It checks values on a document against your own lists, such as your vendor list.

You can also add a check that only your plant needs, such as a pallet-to-carton conversion, as a step you set up in the workflow.

Fields the software is unsure about go to a person. Clicking a field highlights the line on the page that it came from. Docsumo also flags an invoice that duplicates one already received, which duplicate invoice detection covers in more depth.

On the Business plan, Docsumo routes invoices for approval by the rules you set. A rule can use any field, such as the amount, the vendor or the cost center. Approvers get an email, and an invoice that isn't approved in the time you set is escalated. The audit log records each approval decision.

Checked data goes to your ERP through the API and webhooks. Docsumo doesn't create POs, and it doesn't pay vendors, so ordering and payments stay in the systems you use now. Docsumo is cloud only.

For the ordering side, see the purchase order process and purchase order automation. If you also pay carrier freight bills, the logistics page shows the carrier documents Docsumo reads. The accounts payable page shows the whole AP workflow.

How to test AP automation on your own invoices#

Run any tool you're considering on a week of your own invoices, with the POs and receipts behind them.

1. Pick the hard invoicesTake your longest invoice, one from a split delivery, one billed in different units from the receipt and one with freight or surcharge lines.
2. Bring the other documentsAdd the PO and the receipt for each invoice, in the form your team gets them, scans and handwriting included.
3. Count what a person fixedFor each invoice, count the lines that someone had to correct or match by hand.
4. Follow the exceptionsCheck that each invoice on hold shows the reason and reaches the right person, such as the receiving team or the buyer.
5. Check the handoffConfirm that the checked data reaches your ERP in the format it needs.

If your receiving team still signs paper receipts#

At Oakline, a signed paper receipt was what caught the missing pallet. A receipt like that is the most important record for the match. It may also be the last record to reach AP. So first, change how receipts reach AP. Scan each receipt the day it's signed, and send it to the same place as the invoices. A match can then run as soon as AP has both documents, without waiting for someone to type the receipt into the ERP.

Book a demo with a week of your own invoices and the signed receipts behind them, or start a free trial.

Frequently asked questions#