What's the Difference Between a Purchase Order and an Invoice?

A purchase order is a request. An invoice is a bill. They usually cover the same order, but they happen at opposite ends of it, and they're created by different people.

Who Creates Each One?

The buyer, meaning the brand or retailer, creates the purchase order. It's their way of telling a factory or supplier exactly what they want, how much, and by when. The seller, meaning the factory or supplier, creates the invoice. It's their way of saying here's what was actually delivered, and here's what you owe for it.

When Does Each One Show Up?

The purchase order comes first, usually weeks or months before anything ships, since it's what kicks off production in the first place. The invoice comes later, generally once the goods have shipped or arrived, since it's tied to what was actually delivered, not just what was originally planned.

Do They Always Match Exactly?

Not always, and that's actually one of the more common sources of confusion in a supply chain. A purchase order might call for a certain quantity, but if a factory falls short during production, or a shipment gets split, the invoice might reflect a different number than what was originally ordered. For example, a purchase order written for 1,200 units might come back on the invoice as 1,140, because a factory ran short on one size or color, or a small batch got held back for a later shipment. This is why teams often compare the two side by side before approving payment, checking that what's being billed actually lines up with what was ordered and what arrived.

Why Does the Difference Matter?

Because mixing the two up causes real problems. Paying an invoice without checking it against the original purchase order can mean paying for goods that were never actually received, or missing a shortfall that should have been flagged. On the other side, a factory that never gets a clear purchase order has nothing solid to base their invoice on, which leads to disputes over price or quantity later. Keeping these two documents distinct, and actually checking them against each other, is one of the simpler habits that prevents a lot of expensive mistakes down the line.

See How OGVI Catches Mismatches Automatically

OGVI checks what was ordered against what actually shipped and what's being billed, so a quantity that doesn't match gets flagged before payment goes out, not after. See how it works at ogvi.ai.