What should a PO include?

A PO should include everything the supplier needs to fulfil correctly and your bookkeeper needs to verify later: a unique PO number (the reference that ties order, delivery and invoice together), your company and the supplier's details, the order date, line items with SKU or description, quantity, unit price and any agreed discounts, expected delivery date and delivery address, payment terms (net 30, etc.), shipping terms, and the name of whoever approved it.

The two most commonly missed: the delivery date (without it, 'late' is unenforceable) and per-line SKUs (without them, receiving can't match what arrived against what was ordered).

Good inventory software fills most of this automatically from supplier and product records — the PO becomes a two-minute task instead of a form-filling chore.