Three documents, one desk
An invoice arrives from a supplier. Before it can be approved, someone has to find the purchase order it relates to, which might be in the purchasing system, a spreadsheet or an email. Then they need to check what actually arrived, which means finding the delivery note, often a signed piece of paper photographed on a phone in the goods-in area. Then they compare line by line: quantity, unit price, item.
When it all agrees, which it usually does, the check was a waste of time. When it does not agree, the discrepancy is often small and needs a phone call to the supplier or the warehouse to understand. Meanwhile other invoices wait in the queue.
Why matching resists simple automation
The idea of three-way matching is simple. The data is not. Suppliers describe items in their own words and with their own codes. Deliveries arrive in part loads against one order. Prices change between order and invoice. Carriage gets added. One invoice covers two orders.
| Mismatch | Usually means |
|---|---|
| Item description differs | Supplier uses its own code or name for your item |
| Quantity invoiced exceeds received | Part delivery, or goods-in not recorded yet |
| Unit price slightly higher | Price rise not reflected on the PO, or a surcharge |
| Extra line on invoice | Carriage, packaging or a small-order charge |
| No PO found | Order raised by phone, or PO number missing from invoice |
Most matching tools stop at the first of these. If the description does not match, they flag it, and because descriptions rarely match exactly, almost everything gets flagged. Staff lose faith in the tool and go back to checking by hand.
The cost of doing it manually
Invoices wait for approval, so suppliers are paid late, and early-payment discounts are missed. Worse, because the check is tedious, it is done quickly, and overcharges that are small per line slip through repeatedly. Nobody notices that one supplier's unit price has crept up across several months because each invoice looked roughly right.
The person doing the matching is usually doing something else too, in purchasing or in accounts, and the matching eats into that.
How we automate the match
- Collect the three sources: purchase orders from your purchasing system, ERP or spreadsheet; receipts from goods-in, including photographed delivery notes read with a document model; and invoices from your capture inbox or accounting system.
- Build a supplier item map: each supplier's description or code is linked to your item code, starting from your past matched invoices and growing as people confirm new mappings.
- Match at line level, handling part deliveries, several invoices per order and several orders per invoice.
- Apply your tolerances: price variance within an amount or percentage you choose, known surcharges such as carriage accepted up to a limit, rounding ignored.
- Route by outcome: fully matched invoices go to Xero, QuickBooks, Sage or your ERP as approved for payment; mismatches go to the right person with the specific difference highlighted.
- Track price movement per supplier and item, so gradual increases show up as a trend rather than being lost invoice by invoice.
The exception view shows the three documents side by side with the disagreeing line marked. Most exceptions can be resolved in one decision: accept, reject, or query the supplier with a pre-filled email.
What your purchasing and accounts teams see
Matched invoices move through without anyone touching them. People work on the ones that disagree, and they can see why straight away. Supplier price rises become visible, which is useful the next time you negotiate. Goods-in recording improves too, because the matching makes it obvious when a delivery has not been booked in.
Approval stops being a bottleneck at month end, and suppliers are paid on the terms you agreed, which tends to make them easier to deal with when you need a favour.
Signs you have this problem
- Invoices sit waiting for someone to find the PO and the delivery note.
- Your current matching tool flags almost everything, so nobody trusts it.
- Delivery notes are paper or photos that never get recorded properly.
- You suspect some suppliers invoice above the agreed price, but cannot prove it.
- Early-payment discounts are missed because approval is slow.