What is a purchase order?
A purchase order (PO) is a buyer's formal offer to purchase goods or services at agreed prices and quantities. Once the vendor accepts it, the PO becomes a binding reference for delivery, invoicing and payment — the vendor's invoice should quote your PO number.
Why small businesses should use POs
- Price protection — the vendor can't bill more than the agreed rate.
- Clean three-way matching — PO → delivery challan → invoice keeps accounts tight.
- Audit trail — numbered POs document who ordered what and when.
- Inventory planning — open POs show stock that is already on the way.