Manufacturing runs on purchase orders. They're the agreed record of what you're buying: the items and quantities, the unit price, the supplier, the delivery date, the payment terms, and the job, product line or cost centre the purchase belongs to. But in manufacturing businesses, much of their value only shows up at payment time, when the invoice arrives and someone has to decide whether to pay it.
Why the PO does more work in manufacturing
A PO carries more weight in a manufacturing business than in most sectors for a few reasons:
1. Volume and variety. A single build can pull dozens of components from different suppliers, so orders are large, multi-line and constant.
2. Split deliveries. One PO is often filled by several deliveries over days or weeks, each with its own goods receipt, and sometimes more than one invoice.
3. Moving prices. On commodities and components, the price quoted isn't always the price billed, so the PO is your reference for what was actually agreed.
4. Cost attribution. For accurate product costing, each purchase has to map to the right job, product line or cost centre rather than a generic expense code.
Each of these makes the PO the reference that links an order to its deliveries, its invoices and its final product cost.
What the invoice is checked against
The PO matters most when the invoice lands because it's what tells you whether to pay it. In practice that means a three-way match, lining up the purchase order, the goods actually received and the supplier's invoice. When they agree, payment is straightforward. And when they don't, the PO surfaces the problem. This could be an invoice for more than was ordered, a price that has crept up, a delivery that never arrived, or the same invoice billed twice.
With one PO spread across multiple receipts and invoices, and often hundreds of orders open at once, mismatches are frequent and easy to miss. But when the PO is matched properly it is what catches them before the money goes out.
The cost of getting it wrong
Skip or fumble the match and the damage can run well past overpaying a supplier. In manufacturing, purchase data feeds stock valuation and product costing, so a wrong price or quantity distorts what you think each product costs to make and what your inventory is worth, as well as what you paid on the invoice.
Doing the matching by hand across that volume also comes at a cost because keying errors flow into the ledger. That then means more finance time spent reconciling instead of analysing.
Where Moss fits
Moss helps many manufacturing businesses automate their accounts payable, and PO matching is at the centre of it. When a supplier invoice arrives, Moss reads it and links it to the right PO, by the PO number on the invoice or, failing that, by supplier and an invoice date within a week of the PO date. It then checks the invoice total against the PO with no tolerance at all: if the invoices against a PO add up to more than was approved, even by a penny, or the supplier doesn't match, the invoice goes back for approval rather than through to payment.
For goods, whoever receives the delivery records the quantities as a goods received note, partial deliveries can be logged as they arrive, and the accountant matches invoice to receipt before it is paid. A PO shows as partially or fully invoiced, so a second invoice against a completed order stands out. The matching itself is automatic; a person only looks at the exceptions.
The PO's accounting details, the cost centre or job it was raised against, are copied onto the matched invoice, automatically where the lines correspond and for review where they don't, and carry through the ERP sync to the ledger, so product costing gets the coding that was agreed at order rather than one re-keyed from the invoice. Moss doesn't replace your ERP or production system, and VAT and tax treatment stay with your accounting system; its job is to make sure the spend data feeding them is right before it gets there.
The PO is only as good as the match
A purchase order records what you agreed to pay for. In manufacturing, where one order becomes many deliveries and invoices and every figure feeds product costs, it only holds if order, delivery and bill still agree at payment. Checking that accurately, at manufacturing volume, is what turns a PO from a filing step into a control on spend.
