Is a Purchase Order a Contract? PO vs Contract Explained
A PO can be a binding contract, but only once the vendor accepts it. When that happens, and when a PO alone isn't enough.
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Short answer: a purchase order on its own is an offer. It becomes a binding contract once the vendor accepts it. For most everyday buying that is all you need. For bigger, longer or riskier supply you want a proper contract as well, with POs issued under it.
This isn't legal advice, and for anything high-value you should have a lawyer look at your terms. But the basics are simple enough to get right on your own.
How a PO becomes binding
Under the Indian Contract Act, 1872, a contract needs an offer, an acceptance and consideration. When you send a PO you are making an offer: we will buy these goods at this price on these terms. The vendor can accept in writing, by signing a copy or sending an order acknowledgement, or by conduct, for example by dispatching the goods. Section 8 of the Act treats performing the conditions of an offer as acceptance.
Once it's accepted, both sides are bound: the vendor to supply as described and you to pay as described. Before that point you can usually withdraw or change the PO without much trouble.
PO vs contract, side by side
| Purchase order | Supply contract | |
|---|---|---|
| Covers | One order: specific items, quantities, price and delivery date | A relationship: terms that apply to many orders over a period |
| Length | One or two pages | Often ten pages or more |
| Runs for | Until that order is delivered and paid | Usually a year or more |
| Drafted by | The buyer's system, from a template | Procurement or lawyers, negotiated with the vendor |
| Usually includes | Delivery terms, payment terms, a link to standard terms | Liability limits, warranties, IP, confidentiality, termination, disputes |
| Right for | Routine, low-risk purchases | High-value, long-term, custom or critical supply |
When a PO alone is fine
For most purchases a PO with your standard terms attached is enough: office supplies, standard spares, one-off services, small capex. The PO says what you're buying, and your terms (printed on the back or linked from the PO) cover inspection, rejection and late delivery.
When you need a contract as well
- You buy the same thing repeatedly over a year and want fixed prices. That is a rate contract, and each order is a PO issued against it.
- The item is custom, like a mould, a fabricated structure or software built for you, and the specification and acceptance tests need more detail than a PO can hold.
- A failure would be expensive: a critical raw material, a sole supplier, or anything that could stop your line.
- Intellectual property, confidential information or personal data is involved.
- The vendor takes on real liability, such as installation at your site or services your customers depend on.
In these cases the usual setup is a master agreement that holds the legal terms, with a PO for each order under it. The PO then only needs the commercial details and a reference to the agreement.
When your terms and theirs disagree
A common mess: your PO says payment in 60 days on your terms. The vendor's quotation said 30 days on theirs, and their acknowledgement repeats their terms. The goods arrive, you pay on day 60, and they chase you for interest. Whose terms apply?
It depends on the full exchange, and it can go either way. The practical fix is to settle it before anything ships. State on the PO that your terms override anything in the vendor's quotation, and ask for a signed acknowledgement. For important suppliers, sign a master agreement once and the question doesn't come up again.
Payment terms and MSME suppliers
There is one thing a PO can't override. If your vendor is a registered micro or small enterprise, the MSMED Act, 2006 requires you to pay within the agreed period, and that period can't be longer than 45 days from acceptance of the goods or services. If no period is agreed, the limit is 15 days. Late payments carry compound interest at three times the RBI bank rate. On top of that, since FY 2023-24, Section 43B(h) of the Income Tax Act only allows you to deduct an amount owed to a micro or small supplier in the year you actually pay it, if you pay after that limit. So a PO with 90-day terms to a small MSME vendor is a problem, whatever they signed.
What every PO should carry
With or without a contract behind it, a PO should have:
- A unique PO number and a date
- Your legal entity name, GSTIN and billing address, plus the delivery address
- Item descriptions, HSN codes, quantities, units and unit prices
- Tax shown separately from the price
- The delivery date and delivery terms, including who pays freight
- Payment terms
- A reference to your terms and conditions, or to the master agreement it falls under
Our purchase order format has all of these laid out if you want a starting point.
Frequently asked questions
Is a purchase order legally binding in India?
Yes, once the vendor accepts it. Acceptance can be in writing, such as a signed copy or an acknowledgement, or by conduct, such as dispatching the goods. Before acceptance a PO is only an offer.
What is the difference between a PO and a contract?
A PO covers one specific order. A contract, or master agreement, sets the terms for a whole relationship and usually runs for a year or more, with individual POs issued under it.
Can a purchase order be cancelled?
Before the vendor accepts it, generally yes. After acceptance, cancelling can be a breach unless your terms allow it, and the vendor may claim costs they have already incurred.
What is a PO agreement?
People use the phrase for two things: an accepted purchase order, or a framework agreement under which POs are issued. The second is more often called a master supply agreement or a rate contract.