Question 1

What is the difference between a purchase order and an invoice?

Accepted Answer

A purchase order is created by the buyer and sent to the seller at the start of a transaction, requesting specific goods or services at an agreed price. An invoice is created by the seller and sent to the buyer after the goods or services have been delivered, requesting payment. The two documents usually reference each other — a correctly drafted invoice cites the PO number, and a correctly processed PO generates a matching invoice — which allows the buyer's accounting department to verify that what was ordered, what was delivered, and what is being billed all line up. This three-way match is the foundation of accounts payable controls in most mid-sized and larger businesses.

Question 2

Is a purchase order a legally binding contract?

Accepted Answer

Yes, once it is accepted by the seller. Under Article 2 of the Uniform Commercial Code (UCC), which governs the sale of goods in almost every state, a purchase order is generally treated as an offer to buy, and the seller's acceptance — whether by written acknowledgment, shipping the goods, or beginning performance — forms a binding contract. Once accepted, the PO commits the buyer to pay for the goods as specified and the seller to deliver them on the agreed terms. Because of this, PO language should be as clear and specific as any other contract: quantity, price, delivery terms, quality requirements, and any warranty expectations.

Question 3

What is a PO number and why does it matter?

Accepted Answer

A PO number is a unique identifier assigned by the buyer to each purchase order. It matters because it ties together every document related to a single order — the PO itself, the packing slip, the vendor invoice, the receiving report, and the payment. Accounts payable departments refuse to process invoices that do not reference a valid PO number because it bypasses the buyer's authorization controls. Most accounting systems auto-generate sequential PO numbers (PO-2026-0001, PO-2026-0002), though some companies prefix them with a department or cost center code for easier sorting and reporting.

Question 4

What is a blanket purchase order?

Accepted Answer

A blanket purchase order (sometimes called a standing order) is a single PO that covers multiple deliveries from the same vendor over a defined period — typically a quarter or a year — at agreed prices. Instead of issuing a new PO every time the buyer needs more inventory or services, the buyer releases against the blanket PO, which simplifies procurement, reduces paperwork, and often unlocks volume discounts. Blanket POs are common for office supplies, maintenance services, raw materials, and recurring professional services. They should include a maximum quantity or dollar cap and a clear expiration date so the commitment doesn't become open-ended.

Question 5

Can I cancel a purchase order after sending it?

Accepted Answer

It depends on whether the seller has accepted the PO and whether performance has begun. Before acceptance, the buyer can generally cancel without penalty because no contract has formed. After acceptance but before shipment, cancellation may be possible but the buyer may owe reasonable cancellation fees — especially if the seller has already ordered materials, committed labor, or produced custom items. After shipment, cancellation typically requires the seller's agreement and may involve restocking fees, return freight, or forfeited deposits. The PO terms should spell out the cancellation policy clearly to avoid disputes.

Question 6

What payment terms should I put on a purchase order?

Accepted Answer

Payment terms should be explicitly stated on the PO so both sides agree from the start. The most common terms are Net 30 (payment due 30 days after invoice date), Net 15, Net 45, or Net 60. Some buyers negotiate early-payment discounts like '2/10 Net 30,' meaning a 2 percent discount if paid within 10 days instead of the full 30. Large corporate buyers sometimes use Net 90 or even Net 120, which shifts working capital burden onto the seller. The PO should also name the accepted payment methods (check, ACH, wire, credit card) and the billing address for the invoice.

Question 7

What is a three-way match in accounts payable?

Accepted Answer

A three-way match is an internal control process where the accounts payable department compares three documents before paying a vendor: the purchase order (what was ordered), the receiving report or packing slip (what was actually delivered), and the vendor invoice (what is being billed). Only if all three agree on quantity, price, and line items will the invoice be approved for payment. The three-way match protects against overbilling, duplicate invoices, fraud, and delivery shortages, and it is one of the most important procure-to-pay controls. Exceptions get flagged to a procurement manager for investigation.

Question 8

Do I need a written contract in addition to a purchase order?

Accepted Answer

For simple, routine purchases of standard goods, the PO itself is often sufficient because the UCC fills in most of the default contract terms. For larger, more complex, or higher-risk purchases, most buyers also use a master purchase agreement or vendor contract that defines the broader relationship — warranties, indemnities, IP ownership, confidentiality, insurance, and dispute resolution — and then issue individual POs for specific orders under that master agreement. This two-layer structure keeps individual orders simple while locking in the important legal protections once at the relationship level.

Question 9

What happens if the goods delivered don't match the purchase order?

Accepted Answer

Under the UCC's perfect tender rule, the buyer generally has the right to reject goods that do not conform exactly to the PO, though in practice most buyers try to resolve minor discrepancies through a variance or field adjustment. If the wrong quantity, item, grade, or quality is delivered, the buyer should document the discrepancy in a receiving report, notify the seller in writing within a reasonable time, and either reject the non-conforming goods, accept them at a negotiated price reduction, or demand correction. Accepting the goods without objection can waive the right to later complain, so prompt inspection and written notice are important.

Item	Qty	Unit	Price	Total
1/4" mild steel plate, 4x8	24	sht	$148.00	$3,552.00
2" square tube, A500 grade B	60	ft	$9.25	$555.00
Stainless rod, 1/2" x 6ft	16	ea	$22.40	$358.40

Free Purchase Order Forms

What Is a Purchase Order?

Binding Contract

Spending Control

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PURCHASE ORDER

Purchase Order vs Invoice

Purchase Order

Invoice

How to Create a Purchase Order

Assign a unique PO number

Enter your company and vendor details

Itemize the order

Add tax, freight, and discounts

State payment and delivery terms

Attach terms and conditions

Get internal approval and send

Key Components of a Purchase Order

PO number and date

Buyer information

Vendor information

Ship-to address

Line items

Subtotal, tax, and freight

Payment terms

Delivery terms

Terms and conditions

Authorized signature

Sample Purchase Order

PURCHASE ORDER

Frequently Asked Questions

Official Resources

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