How to write a purchase order (with an example)

Published 17 October 2026 · Freelancing and getting paid

A purchase order, or PO, is the buyer's written instruction to a supplier: what to provide, in what quantity, at what price and by when. A useful PO gives the supplier enough detail to fulfil the order and finance enough detail to approve the invoice. It is not proof that the goods arrived or that payment was made.

Know where the PO fits

A quote offers a price; the buyer's purchase order places the order; the supplier's invoice requests payment; a receipt records payment. The quote, estimate and invoice guide explains the wider sequence. Do not send a PO as though it were a customer invoice.

A PO can form part of a contract, but its effect depends on acceptance, existing agreements and applicable law. Check conflicting supplier terms before delivery. The US UCC sources below illustrate offer, acceptance and additional terms for goods; they are not universal rules for every purchase or jurisdiction.

Add the parties and an unambiguous reference

Use the buyer's and supplier's legal names, addresses and contacts. Separate the billing address from the delivery address. Add a unique PO number, issue date, currency and the approved quote or contract reference. If a project or department pays the bill, include its reference too.

Choose a numbering system that does not reuse numbers, such as PO-2026-0042. A revision should retain that reference and identify its revision number and date. Tell the supplier where to send acknowledgements and invoices, and ask them to include the PO number on both.

Describe line items so substitutions are visible

Give each item a clear description, product code where useful, unit, quantity and unit price. Include sizes, specifications or an attached specification version when a name alone is ambiguous. For services, state the deliverable or service period rather than only “professional services.”

Show discounts, shipping and taxes separately, and say whether prices include tax. Do not mix currencies in one total. If tax is uncertain, resolve it with the supplier rather than inserting a guessed rate into the final order. Arithmetic and tax compliance are different checks.

A worked purchase order example

Suppose a studio orders display materials from a print supplier. This example uses USD, no discount, USD 20 shipping and an illustrative 10% tax applied only to the goods. Real tax rates and whether shipping is taxable depend on the transaction; these assumptions are only for checking the sums.

Item	Quantity	Unit price	Line total
Display stands, specification A	12	USD 25	USD 300
Printed signs, approved artwork v3	4	USD 40	USD 160
Goods subtotal			USD 460
Shipping			USD 20
Illustrative tax: 10% of USD 460			USD 46
Order total			USD 526

The buyer should also state the delivery address, required date and approved artwork attachment. Check that 12 × 25 plus 4 × 40 equals 460, then add the agreed shipping and tax. The supplier's acknowledgement should confirm the same specification and total, not only the PO number.

Specify delivery, inspection and changes

Set the requested delivery date or schedule, delivery location and contact. Say whether partial deliveries or substitutions are acceptable and how shipping charges are agreed. For international or higher-risk purchases, obtain advice about delivery terms, customs responsibilities, insurance and when risk passes.

Explain the inspection or acceptance process and how shortages, damage or non-conforming work should be reported. A delivery signature may acknowledge receipt without confirming that every item passed inspection; make the intended process clear. Do not promise a rejection window that conflicts with mandatory rights or an existing contract.

Please acknowledge PO-2026-0042 and confirm the quantities, specification, total price
and delivery date before dispatch. No substitution or additional charge is authorised
without the Buyer's written agreement. Quote this PO number on delivery documents
and invoices. Send any proposed change to [named contact and address].

This is sample operational wording, not a complete set of purchase terms. Add the actual contact and agree the legal terms separately where needed.

Agree payment terms and approval authority

Record when payment becomes due and what starts the clock: for example, receipt of a correct invoice, subject to the agreed contract and lawful acceptance process. “Net 30” is incomplete if the parties disagree about the starting date. The invoice due date calculator helps turn agreed terms into a date.

Identify the person authorised to approve the order and any spending limit. A draft PO should not look like a released order. Keep internal approval evidence, then send the approved version to the supplier and retain their acknowledgement. Check payment-detail changes through a known contact rather than trusting a new bank account printed on an email.

Match the order, delivery and invoice

Before paying, compare three records: the approved PO, the receiving or acceptance record, and the supplier's invoice. Check quantities actually received, unit prices, approved extras, taxes, currency and prior payments. For a partial shipment, pay according to the agreement and keep the remaining quantity open rather than treating the order as fully delivered.

Resolve mismatches before silently editing the order to fit the invoice. If the scope changed, retain the agreed revision or change order. If the supplier corrects a billed amount, keep the replacement invoice or credit note with the transaction. This trail helps prevent duplicate payments as well as disputes.

Make the next order easier

Reuse supplier and buyer details, but recheck delivery addresses and contacts.
Give each new order its own number; do not copy the previous order's quantities blindly.
Keep approved specifications, revisions, delivery evidence and invoices together.
Close the order only after the agreed deliveries and financial adjustments are complete.

The free purchase order template calculates line totals and tax when filled in online and downloads as editable Word. Review its assumptions and the final file before sending. Suppliers preparing the related bill can use the invoice writing guide.

General purchasing and drafting information, not legal, accounting or tax advice. Adapt the terms to the transaction and local rules.

Sources

Questions

Is a purchase order the same as an invoice?

No. The buyer issues a purchase order to order goods or services; the supplier issues an invoice to request payment. Quote the PO number on the invoice so the order, delivery and bill can be matched.

Is a purchase order legally binding?

It can form or evidence a contract, depending on its terms, acceptance, any existing agreement and applicable law. A supplier acknowledgement with different terms needs review; do not assume your wording automatically overrides theirs.

Can I change a purchase order after sending it?

Send a clearly numbered revision or agreed change order and obtain the supplier’s agreement where required. Keep the earlier version and record what changed. Quietly replacing the original file makes later delivery and invoice disputes harder to resolve.

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