What Is a Purchase Order? Definition, Examples & Free Template

What Is a Purchase Order?

A purchase order (PO) is a commercial document a buyer sends to a supplier to confirm an order - specifying the items, quantities, agreed prices, delivery terms, and payment terms. Once the supplier accepts the PO, it becomes a legally binding agreement between buyer and seller. Every PO carries a unique purchase order number (PO number) used to track the order through delivery, invoicing, and payment.

In plain terms: a purchase order is the buyer's formal 'I want to buy this, at this price, delivered by this date.' It is the document that turns a negotiated quote into a committed order, and it is the anchor for three-way matching when the invoice arrives.

What a Purchase Order Includes

A standard purchase order contains these fields, in a consistent purchase order format:

• PO number - unique identifier for tracking
• Issue date and delivery date
• Buyer details - company name, address, contact, tax ID
• Supplier (vendor) details - company name, address, contact
• Ship-to address - where goods should be delivered
• Line items - item name, description, quantity, unit, unit price, amount
• Subtotal, taxes, freight, and grand total
• Payment terms and Incoterms (e.g. Net 30, FOB Origin)
• Validity period - how long the PO prices are valid

Purchase Order Example

A simple purchase order example: a manufacturer issues PO-2026-0042 to SteelCo for 500 kg of Grade A 12mm steel rods at $2.10/kg, delivered FOB Origin to their Houston warehouse by September 15, 2026, with Net 30 payment terms. The grand total is $1,050 plus freight and tax. SteelCo acknowledges the PO, ships the rods, and invoices against PO-2026-0042 - accounts payable then three-way matches the PO, receipt, and invoice before paying.

Purchase Order vs Invoice

The core difference: a purchase order is sent by the buyer before delivery to place the order. An invoice is sent by the supplier after delivery to request payment. The PO says 'here is what I want'; the invoice says 'here is what you owe.' Both share a similar line-item format but serve different stages of the transaction. See purchase order vs invoice for the full breakdown.

Purchase Order vs Purchase Requisition

A purchase requisition is an internal request - an employee or department asking to buy something, routed for approval. A purchase order is the external commitment sent to the supplier after the requisition is approved. The requisition comes first; the PO follows. See purchase requisition.

Types of Purchase Orders

There are four main types of purchase orders, each for a different purchasing situation:

• Standard purchase order - one-time order for specific items, quantities, and dates (most common)
• Blanket purchase order - a single PO covering multiple deliveries over a period, with agreed pricing but flexible call-offs. See blanket purchase order.
• Contract purchase order - a framework PO setting terms for future, separately-released orders
• Planned purchase order - a PO with expected items and quantities but tentative delivery dates, firmed up later

The Purchase Order Process in 7 Steps

A structured purchase order process keeps purchasing controlled and auditable:

• 1. Need identified - a purchase requisition is submitted
• 2. Approval - the requisition is reviewed and approved
• 3. Supplier selected - via RFQ, existing contract, or catalog
• 4. PO created - with all line items, prices, and terms
• 5. PO sent to supplier - and acknowledged (see purchase order acknowledgment)
• 6. Goods received and inspected - receipt recorded
• 7. Invoice paid - after three-way matching

How to Create a Purchase Order for Free

You can create a purchase order in under 2 minutes using the free AuraVMS purchase order generator - no signup, no watermark. Fill in basic details, buyer and vendor, shipping, line items, and terms; the tool calculates totals automatically and downloads a print-ready PDF. For ongoing PO management across suppliers, the full AuraVMS product starts at $4.99/month.

Frequently Asked Questions

Is a purchase order legally binding?

Yes. Once the supplier accepts a purchase order, it becomes a legally binding contract between buyer and seller. The PO specifies items, quantities, prices, delivery terms, and payment terms - and both parties are obligated to fulfill them. This is why PO approval workflows matter before the PO is sent.

What is a PO number?

A PO number is the unique identifier on a purchase order, used to track the order through delivery, invoicing, and payment. Common formats are PO-2026-0001 or 26-0001. Suppliers print the PO number on the invoice so accounts payable can match the invoice to the order. See purchase order number.

Do I need a purchase order for every purchase?

For controlled, auditable procurement - yes. POs enforce spend control, create an audit trail, and enable three-way matching. For very small or one-off purchases, many SMBs use a purchase requisition or a corporate card instead, but anything above a defined threshold should flow through a PO.

What is the difference between a PO and an invoice?

A purchase order is sent by the buyer before delivery to place the order. An invoice is sent by the supplier after delivery to request payment. The PO initiates the transaction; the invoice requests payment for it. See purchase order vs invoice.

Can I create a purchase order for free?

Yes. The AuraVMS free purchase order generator lets you create a professional PO and download the PDF instantly - no signup, no watermark, no limit on the number of POs.

What is a blanket purchase order?

A blanket purchase order is a single PO covering multiple deliveries over a set period, with agreed pricing but flexible quantities and call-off dates. It is used for recurring purchases from a supplier to lock in pricing without re-issuing a PO every time. See blanket purchase order.