Direct comparison
Purchase Order vs Sales Order: Key Differences
Purchase order vs sales order: who issues each, which comes first, how UCC 2-206 and 2-207 treat them, and the PO to sales order to invoice chain.
Written and maintained by CASRAI Editorial Board
Last updated
How do Purchase order (PO) and Sales order compare side by side?
The table below compares Purchase order (PO) and Sales order across 10 dimensions, from who creates it to when to pick each.
Side-by-side comparison
| Dimension | Purchase order (PO) | Sales order |
|---|---|---|
| Who creates it | The buyer, as its order to a supplier. In UCC 2-206 terms, it is the "order" or offer that invites acceptance. | The seller. Microsoft Dynamics 365 Supply Chain Management describes a sales order as representing "a sale of a product to a customer". |
| Which comes first | Normally first: it starts the transaction from the buyer side. | Follows the customer's order. In Dynamics 365, a sales order can be archived only once it is fully invoiced; the sources do not state a formal order of documents, so this is an inference. |
| Role in forming a contract (model UCC text) | An offer "inviting acceptance in any manner and by any medium reasonable in the circumstances" (UCC 2-206(1)(a)). An order for prompt or current shipment invites acceptance by a prompt promise to ship or by prompt shipment (2-206(1)(b)). | The UCC text reviewed does not use the term sales order, and no standard defines it. It is the seller's internal record. A seller's written confirmation of an order can operate as an acceptance (UCC 2-207(1)); whether the record itself is that confirmation depends on what is sent. |
| If the two documents carry different terms | Between merchants, the seller's additional terms become part of the contract unless the offer expressly limits acceptance to its terms, they materially alter it, or the buyer objects within a reasonable time (UCC 2-207(2)). | A confirmation with additional or different terms still operates as acceptance unless it is expressly made conditional on assent to those terms (UCC 2-207(1)). Additional terms are "proposals for addition" (2-207(2)). |
| Silence and timing | Where beginning performance is a reasonable mode of acceptance, an offeror not notified of acceptance within a reasonable time may treat the offer as lapsed (UCC 2-206(2)). | Shipment of non-conforming goods is not an acceptance if the seller seasonably notifies the buyer that the shipment is offered only as an accommodation (UCC 2-206(1)(b)). |
| What it typically records | The buyer's request. Its terms are covered in the CASRAI guide to purchase order terms and conditions. | In Dynamics 365: the customer, charges on items such as freight or installation, and delivery options such as different times or locations. |
| Sales order vs invoice | A PO is not a bill. The PO versus invoice difference has its own CASRAI comparison. | In Dynamics 365 a sales order is archived only once it is fully invoiced; Microsoft notes this, and the records are kept for reporting, auditing and legal claims. |
| What each commits the buyer to | The PO is the buyer's offer, so it is the document the buyer would be held to if the seller accepts it as written (editorial reading of UCC 2-206). Whether it binds depends on acceptance and the governing law. | The sales order is the seller's record, so it is the place to check what the seller understood the buyer ordered. Terms in the seller's confirmation bind only as UCC 2-207 allows. |
| Clinic or reseller account | Keep a copy of the PO you issued, with its reference number, as the baseline for what you asked for. | Ask for the seller's sales order or acknowledgment, then compare it with your PO before shipment. This is an editorial workflow suggestion built from UCC 2-207, not a requirement stated by a source. |
| When to pick each | Use a PO when you are the buyer placing an order. | Use a sales order when you are the seller recording and fulfilling an order. Buyers do not issue one; they review the seller's version. |
Sources
- Cornell LII, UCC 2-206 and 2-207 (model text; states differ in enactment), checked 2026-11-03
- Microsoft Learn, "Sales order" (Dynamics 365 Supply Chain Management), ms.date 2026-03-04, checked 2026-11-03
Ask CASRAI · free to try
Ask about Purchase Order vs Sales Order: Key Differences
Ask your first 2 questions free below. Subscribers get 150 a day for $29 a month.
An AI assistant specialized in research administration. It cites the sources behind every answer, labels web answers and says when it can't answer.
Answers draw on CASRAI's guides and dictionary plus the federal and funder documents we index: Federal Register, Grants.gov, Regulations.gov and UKRI.
Works on this site and inside Claude, Cursor and the AI tools you already use.
Everything CASRAI publishes — this page, the dictionary, the guides and the news — stays free to read, with no account and no card.
Common questions
Common questions about Purchase order (PO) vs Sales order
What is the difference in purchase order vs sales order?
+
A purchase order is created by the buyer to order goods. A sales order is created by the seller to record the sale; Microsoft describes it as representing a sale of a product to a customer. They are two sides of the same transaction, not alternatives.
Which one applies to a clinic or reseller account?
+
Both. The clinic or reseller as buyer issues the PO. The supplier creates its own sales order or acknowledgment from it. Keep both and check they match before the order ships. See the CASRAI guides on order acknowledgment and purchase orders for medical supplies.
What does each cost or commit the buyer to?
+
Neither document sets a price by itself, and this page makes no price claims. Under the model UCC, a PO is an offer that the seller can accept by promising to ship or by shipping (2-206). The seller's confirmation can operate as acceptance even with different terms unless it is expressly conditional (2-207). What binds in practice depends on the governing law; this is not legal advice.
How do I choose between them?
+
You usually do not choose. If you are ordering, you issue a PO. If you are selling, you create a sales order. The question for a buyer is which document governs when the two differ, and UCC 2-207 sets the model rules for that between merchants.
Which comes first, a sales order or a purchase order?
+
The purchase order comes first, from the buyer. The sales order is the seller's record that follows it and precedes the invoice.
How is a sales order different from an invoice?
+
A sales order records the sale and its delivery details before billing. In Dynamics 365 it cannot be archived until it is fully invoiced, which places it ahead of the invoice in the order-to-cash flow.
