Purchase order (PO)
The document you send a supplier to order goods, stating items, quantities, rates and terms. It is what the delivery and the bill are checked against.
A purchase order turns a phone call into a record. It states what you ordered, at what rate, in what quantity, by when, and on what terms — before the goods arrive and before anyone has an incentive to remember it differently.
What it protects you from
Rates that quietly change between the quote and the bill. Quantities delivered short. Items you never ordered arriving with the consignment. Free-goods schemes that were promised and then forgotten. All of these are cheap to settle against a PO and expensive to argue without one.
Partial deliveries are normal
A supplier sends 60 of the 100 pieces you ordered. The PO stays open for the balance, and you should be able to see at a glance what is still due and how long it has been due. An order tracked only in a diary ends up either double-ordered or forgotten.
Where the numbers should come from
A good PO is not typed from scratch. It comes from what you are short of — reorder points, current stock net of what is already committed, and what is already on the way from another order.
How KillStock handles it
On the Growth plan and above, suppliers and purchase orders are tracked with partial or full goods receipts against the PO, and reorder rules per item and location suggest what to buy after netting reserved stock and backorders. A supplier invoice can be photographed and its lines, taxes and totals reconciled to the PO.
A common mistake
Raising the PO after the goods have arrived, to complete the file. It records history and prevents nothing.