Does a purchase order guarantee payment?

No — a purchase order is not a payment guarantee; it's a commitment to buy. Once the supplier accepts it, the PO is a binding contract, so the buyer owes payment if the supplier delivers as agreed — but 'binding' still means payment can be legitimately withheld for non-delivery, wrong goods or failed quality checks, and it offers no protection at all if the buyer simply can't pay (insolvency).

For suppliers, a PO from a solid customer is strong evidence of a committed sale — good enough to start work and to show a lender — but it isn't cash or credit security. Suppliers who need certainty use deposits, letters of credit or trade credit insurance on top.

For buyers, the flip side matters too: an accepted PO isn't casually cancellable. Treat sending one as seriously as signing.