Purchase Requisition vs Purchase Order: The Difference

A purchase requisition (PR) is an internal request to buy something. A purchase order (PO) is an external, legally binding commitment to a supplier. The requisition asks for permission. The purchase order makes the promise.

That is the whole distinction, and it is why the order matters: the requisition comes first, and the purchase order should not be issued until the requisition is approved.

Simple enough on paper. In practice, this handover is where growing companies quietly lose time and money, because it often happens in someone’s inbox and nobody can prove later what was agreed. This guide covers the difference, the PR to PO process step by step, what each document should contain, and where the process usually breaks.

Purchase requisition vs purchase order: the difference in one table

The row that catches people out is legally binding. A requisition costs nothing if it is declined. A purchase order, once the supplier accepts it, is a contract. That is exactly why approval has to happen before the PO, not after.

The PR to PO process, step by step

Every business tailors the flow to its own approval rules, but the core sequence looks like this:

1. Raise the purchase requisition. Someone needs goods or a service and fills in a PR: what, how many, why, roughly how much, and which budget it comes from.
2. Approve the requisition. It goes to whoever can approve that amount, usually the head of department, and often procurement or finance as a second check. If it is rejected (for example, there is no budget), the process stops or goes back to step 1.
3. Get quotations. For anything beyond routine spend, procurement asks suppliers for quotes and compares price, payment terms, reliability and lead time. Many businesses set a minimum number of quotes above a certain value. The Supplier Quote Control Checklist (PDF) sets out 10 questions to ask before you approve a quote.
4. Select the supplier. The best quotation is chosen and the reason is recorded with the request.
5. Issue the purchase order. Procurement raises a PO against the approved requisition and sends it to the supplier. This is the handover from internal request to external commitment.
6. Supplier accepts. The supplier confirms the PO, or asks for changes. Once accepted, it is binding on both sides.
7. Receive the goods or service. Someone checks what actually arrived, in the right quantity and condition, and records a goods received note. Returns are handled here.
8. Match and pay. The supplier’s invoice is checked against the PO and the goods received note (three-way matching) before payment.

Step 5 is the join between the two documents. It is also the step that most often breaks.

What goes wrong between the PR and the PO

Ask procurement teams at growing companies where the process falls over and the same answers come up.

The PO goes out before the approval. The supplier needs an answer today, so the PO is issued and the approval is “sorted later”. The company is now committed to spend nobody signed off, and if the invoice is queried months later there is no approval trail.

Nobody knows who should approve it. The usual approver is on leave, or the threshold is unclear, so the requisition sits in an inbox while everyone waits.

The supplier invoices without a PO number. Finance now has an invoice it cannot match, and starts asking around to find out who ordered it. This is usually a sign that step 5 was skipped.

The PO does not match what was requested. The quantity or price changed and the requisition was never updated, so the record says one thing and the invoice says another.

Everything lives in email. The request is a chat message, the approval is a “yes, fine” reply and the quote is an attachment on someone’s laptop. When the decision has to be reconstructed later, none of it can be found.

Spend is only visible after it has happened. Budget control becomes reporting, not control.

None of these are paperwork problems. They are process problems, and the paperwork is just where they show up.

What a purchase requisition should contain

Keep the form short enough that people actually fill it in, and specific enough that an approver can decide without a follow-up email:

• What is being requested (item or service, and the specification)
• How many, and the unit of measure
• Why it is needed (the business reason)
• Estimated cost and currency
• Cost centre, department or project it should be charged to
• When it is needed by
• Preferred supplier, if there is one, and why
• Requester and date

If approvers keep replying “what is this for?”, the form is missing a justification field. That is usually the fix.

What is a purchase order?

A purchase order is an official document a buyer sends to a supplier confirming exactly what is being bought: the items or services, quantities, agreed prices, delivery details and payment terms. Once the supplier accepts it, it becomes a legally binding agreement between the two businesses.

Purchase orders matter because they:

• Control spend: purchases are tied to an approved request and budget before money is committed.
• Protect both sides: what was ordered, and at what price, is written down, which makes disputes and unexpected price changes easier to resolve.
• Create an audit trail: auditors can trace each payment back to an order, a delivery and an approval.
• Make invoices matchable: the PO number is the reference that links the order, the delivery and the invoice.

What a purchase order should contain

• A unique PO number: the reference everything else hangs off
• The buyer’s and supplier’s details
• Line items: description, quantity, agreed unit price and total
• Delivery address and date
• Payment terms
• A reference to the approved requisition
• Any terms and conditions that apply

The PO number does more work than people realise. Without it, an invoice cannot be matched to an order and a delivery, and an invoice you cannot match is one you are paying on trust.

The four types of purchase order

Standard PO. A one-off purchase where you know what you want, how many and when. Most spend falls here.

Planned PO. You know what you will need and roughly when, but not the exact delivery dates. Delivery is scheduled against it later.

Blanket PO. An agreement to buy up to a set value or quantity over a period, drawn down as needed. Useful for consumables and repeat spend, so the team is not raising dozens of separate POs.

Contract PO. Terms are agreed up front and individual orders reference the contract. This is where negotiated pricing actually gets enforced.

Purchase order vs invoice, contract and requisition

A sales order is the supplier’s own internal record confirming your PO. You send the purchase order first; the supplier raises a sales order in response.

The part most teams never write down: the approval matrix

An approval matrix answers one question: who can approve what, up to how much, and who takes over when they are away? Here is a simple example. Set the thresholds to suit your own business.

Two rules save the most pain:

Always name a delegate. Every approver needs a named backup. The most common reason a requisition stalls is not disagreement. It is annual leave.

Route by category as well as value. A RM 5,000 legal engagement and RM 5,000 of printer paper should not follow the same path.

Write the matrix down, then compare it with what actually happens. In most companies the gap between the two is the whole problem.

Do you need software to manage PRs and POs?

Not always. With around twenty purchases a month, one location and a few approvers, a well-designed spreadsheet and some discipline can hold.

It stops holding when:

• You have multiple locations or entities, and approval routes differ between them
• Approvals are routinely late, and nobody can say where a request is sitting
• Suppliers invoice without PO numbers, and finance has to chase operations for context
• You need to prove who approved what, and when, and reconstructing it takes days
• Spend is only visible after the money has gone

At that point the spreadsheet is no longer saving money. It is hiding what the process costs.

Frequently asked questions

What do PR and PO stand for?

PR stands for purchase requisition. PO stands for purchase order.

Which comes first, the PR or the PO?

The purchase requisition. It is the internal request; the purchase order is issued after that request is approved. Issuing a PO before the requisition is approved is the most common way companies end up committed to spend nobody signed off.

Is a purchase requisition legally binding?

No. A requisition is an internal document and creates no obligation to anyone outside the business. A purchase order does, once the supplier accepts it.

Can you have a purchase order without a requisition?

Yes, and some companies do, especially for small or routine purchases. The cost is the approval trail, which is exactly what you need when an invoice is queried.

Who raises a purchase requisition?

Whoever needs the item, usually someone in the requesting department. Procurement’s job starts once the requisition is approved.

Can a purchase order be cancelled?

Yes, but because an accepted PO is a commitment to the supplier, cancelling it should be agreed with them, ideally before the goods ship or the work starts. Record the cancellation against the PO so the trail stays complete.

How does a purchase order get paid?

The supplier delivers and sends an invoice that quotes the PO number. The buyer checks the invoice against the PO and the goods received, then pays according to the agreed terms.

What is three-way matching?

Checking the purchase order, the goods received note and the supplier’s invoice against each other before payment. If all three agree, pay it. If they do not, find out why before the money leaves.

Do all businesses need purchase orders?

Very small businesses often manage without them. As purchasing spreads across more people, sites and suppliers, POs become the simplest way to keep spend approved, traceable and easy to match to invoices.

Where ADAM-Procure fits

ADAM-Procure gives growing organisations one place to raise purchase requests, route them through approval workflows built around how the business actually operates, issue purchase orders against approved requisitions, and keep supplier records and quotations together, logged and traceable from request through to invoice.

Download the Readiness Checklist (PDF) →

Or request a 15-minute procurement readiness review.

Related reading

• Procurement documents every buyer should know
• RFI vs RFP vs RFQ vs RFT: which to use, and when
• Vendor management system
• Procure-to-pay software