Direct comparison
Purchase Requisition vs Purchase Order
A requisition is an internal request to buy; a purchase order is the binding document sent to a vendor. How the two differ in lab and research purchasing.
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How do Purchase Requisition, Purchase Order compare side by side?
The table below compares Purchase Requisition, Purchase Order across 9 procurement-relevant dimensions, from what it is through typical failure mode.
Side-by-side comparison
| Dimension | Purchase Requisition | Purchase Order |
|---|---|---|
| What it is | Internal request to purchase | External commercial document sent to a vendor |
| Who creates it | Requester (researcher, lab manager, PI) | Procurement/purchasing office, or a delegated buyer, after requisition approval |
| Where it goes | Stays internal, routed for approval | Sent externally to the vendor |
| Legal effect | None on its own — no external party is bound | Binding contract of sale once the vendor accepts it |
| Typical contents | Item description, estimated price, quantity, account/grant to charge, justification | Vendor name, confirmed price, delivery terms, payment terms, PO number |
| Effect on budget | Creates a soft hold / pre-encumbrance pending approval | Converts the hold into a firm encumbrance |
| Defined under 2 CFR 200? | Not a federally defined term; may be required by institutional policy | Not a federally defined term either — the rule cares about competition method, not document type |
| Common bypass channel | Skipped for very small purchases if policy allows | Replaced by a P-card transaction or a punchout-generated PO for low-dollar buys |
| Typical failure mode | Approval backlog pushes staff to buy informally ("maverick spend") | Issued out of sequence with an already-placed order, or against insufficient remaining budget |
Common questions
Common questions about Purchase Requisition vs Purchase Order
Does a purchase requisition legally commit the institution to buy?
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No. A requisition only documents an internal request and reserves budget. Only a purchase order accepted by a vendor creates a binding commercial commitment.
Can a purchase happen without a requisition ever being created?
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Institutional policy usually requires one above a set dollar threshold. Below that threshold, or where P-card purchases are policy-permitted, a formal requisition may never be generated, but the purchase is still subject to the underlying spending controls and allowability rules.
Does 2 CFR 200 require a purchase order for federally funded purchases?
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No. The Uniform Guidance defines procurement methods by dollar threshold and required competition, not by document type. Whether a formal PO is required for a given purchase is generally an institutional policy decision layered on top of the federal competition rules.
What is the difference between a requisition and an encumbrance?
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A requisition is the request document. An encumbrance is the accounting entry that reserves the estimated, and later PO-committed, amount against a budget so it cannot be double-spent.
Is a blanket purchase order the same thing as a purchase order?
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A blanket PO is a specific type of PO that authorizes repeat purchases from one vendor over a period, up to a set dollar cap, rather than a single one-time transaction. It still follows from an approved requisition, or a standing authorization, the same way an ordinary PO does.
