Purchase orders protect both buyers and sellers. Here's exactly what they are, what goes in them, and when your business should be using them.
What Is a Purchase Order?
A purchase order (PO) is a document a buyer sends to a supplier to formally request goods or services. It specifies exactly what is being ordered, at what price, in what quantity, and by when.
When the supplier accepts the purchase order, it becomes a legally binding contract between the two parties.
Why Purchase Orders Exist
Without a PO, a verbal or email instruction to "send 200 units of product X" has limited legal standing. If the price changes, the wrong product arrives, or a dispute arises about what was agreed, there's nothing to point to.
A purchase order creates a clear paper trail: this is what was ordered, this is the agreed price, this is the delivery date. Both parties have a copy, both parties are bound.
For larger businesses, POs also serve an internal control function — purchases above a certain value require a PO so that spending is tracked and approved before it happens.
What Goes in a Purchase Order?
A standard purchase order includes:
Buyer information — your business name, address, and contact details.
Supplier information — the supplier's name and address.
PO number — a unique sequential number for tracking (e.g. PO-2025-088).
Date — when the PO was issued.
Line items — a description of each product or service, the quantity, the unit price, and the line total.
Delivery date — when the goods or services are expected.
Delivery address — where they should be sent.
Payment terms — how long the buyer has to pay after receiving the goods (e.g. Net 30).
Total amount — the sum of all line items, excluding and including tax.
Authorisation — who in the buyer's organisation approved the purchase.
Purchase Order vs Invoice
A purchase order comes from the buyer to the supplier before the goods are delivered.
An invoice comes from the supplier to the buyer after the goods are delivered.
They are mirror documents. When a supplier receives a PO and delivers the goods, they invoice the buyer for the amount in the PO. The buyer then matches the invoice to the PO to confirm everything was delivered as agreed before approving payment.
This matching process — called three-way matching in accounting — compares the PO, the delivery note, and the invoice to catch discrepancies before any payment is made.
Do Small Businesses Need Purchase Orders?
Not always, but they help in specific situations:
You buy from the same supplier regularly. A PO creates a clear record of each order and prevents disputes about what was agreed.
You have employees making purchases. POs enforce spending approval before money is committed.
Your clients require them. Many larger businesses will not pay an invoice unless it references a valid PO number. If your client sends you a PO, you must reference the PO number on your invoice.
You're managing inventory. POs link incoming stock to specific orders, making it easier to track what's expected and when.
What Happens After a Purchase Order Is Sent?
Purchase Orders in Quotation Expert
Quotation Expert includes a Purchase Orders module where you can create, send, and track POs to suppliers. Each PO is assigned a sequential number, linked to a supplier record, and tracked through to delivery.
When a PO is fulfilled, it feeds into your Bills module — keeping your purchases organised and your accounts accurate. You can see which POs are outstanding, which have been partially fulfilled, and which are fully received.
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