A purchase order (PO) is a commercial document a buyer sends to a supplier to authorize a specific purchase at specific terms. Depending on the terms, supplier response, and applicable law, an accepted PO can become part of the contract record. Done well, the PO is the shared source of truth for the order: what was bought, at what price, on what terms, and when it is expected. Done badly, it is the start of a long email thread.
This guide covers the structure of a modern PO, the fields that matter, the fields that don't, an annotated example, and the automation that makes most of the manual work redundant. If you just need to produce a PO right now, the free purchase order generator builds a fillable, printable PO with every field covered below.
How to write a purchase order
To write a purchase order, give the supplier one unambiguous buying instruction: buyer, supplier, PO number, PO date, ship-to location, line items, quantities, unit prices, delivery window, payment terms, and total. The PO should also state pack size, substitution policy, acceptance deadline, and special receiving instructions when those details matter. A modern purchase order software workflow fills those fields from supplier, inventory, and accounting data so the operator reviews the order instead of typing it from scratch.
The eight core fields
Every useful PO — printed, emailed, sent through WhatsApp, submitted through a portal, or sent by EDI — should include these eight fields. Anything less is closer to a request than an order record.
| Field | Why it matters |
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