Material Requisition vs. Purchase Order: What's the Difference?
On a busy jobsite, "we need more material" can set two very different documents in motion. A material requisition and a purchase order sound interchangeable, and plenty of teams treat them that way—but they do opposite jobs. Confuse the two and you open the door to rogue spending, missing approvals, and job costs that never quite match your estimates.
Here's the clear version, plus how the two are supposed to work together in a healthy field-to-office workflow.
The short answer: A material requisition is an internal request—the field asking the office to get materials. A purchase order is an external commitment—the office telling a supplier "we're buying this, at this price." The requisition starts the process; the purchase order finishes it.
What Is a Material Requisition?
A material requisition is an internal document used to request the materials needed for a job. It usually starts in the field: a foreman or project manager identifies what a crew needs, on which job, and by when, then submits the request to whoever handles purchasing.
The key point is that a requisition is a request, not a commitment. No supplier is involved yet, and no money has been promised. It's the paper trail that says "this need is real, here's who's asking, and here's the job it belongs to"—and that trail is what makes approvals and accurate job costing possible later. If your crews are still submitting these on paper or by text, that's exactly the gap digital field requisitions are built to close.
What Is a Purchase Order?
A purchase order (PO) is an external, legally binding document the buyer issues to a supplier to purchase goods at an agreed price and terms. Unlike a requisition, a PO leaves your company and creates a real commercial obligation: once the vendor accepts it, you've agreed to pay.
A PO also carries the details a requisition usually doesn't—the chosen vendor, agreed pricing, quantities, delivery terms, and a PO number that everything downstream (the delivery receipt, the invoice) gets matched against. Generating that order straight from an approved field request is exactly what construction purchase order software is designed to do.
The Core Difference: Internal Request vs. External Commitment
Strip away the details and it comes down to direction and intent. A requisition points inward—one part of your company asking another to act. A purchase order points outward—your company committing to a vendor. The requisition says "we need this." The purchase order says "we're buying this, from you."
| Material Requisition | Purchase Order | |
|---|---|---|
| Purpose | Request materials for a job | Authorize a purchase from a vendor |
| Direction | Internal (field → office) | External (office → supplier) |
| Who creates it | Foreman or project manager | Purchasing / office |
| Legally binding? | No—it's a request | Yes—a commitment to pay |
| Includes vendor & pricing? | Usually not | Always |
| Triggers | The procurement process | Delivery and invoicing |
How They Work Together: A Field-to-Office Flow
In a well-run operation, the two aren't competing—they're consecutive steps:
1. The field requests
A crew identifies a need and submits a requisition tied to a specific job. Done digitally, this captures the request the moment it happens instead of on a scrap of paper that gets lost by Friday.
2. The office reviews and approves
Purchasing checks the request against the budget and approves it. This is the control step that prevents rogue spending—every dollar about to leave has a name and a job behind it.
3. The approved request becomes a purchase order
Purchasing selects a vendor, locks in pricing, and issues a PO. The internal request has now become an external commitment.
4. Delivery and matching close the loop
The supplier delivers, the goods are received against the PO, and the invoice is matched back to both. Because the original request was tied to a job from the start, those costs land in the right place automatically.
Why the Distinction Matters for Your Bottom Line
When teams skip the requisition and jump straight to ordering, three things tend to break: there's no approval trail, so spending happens without oversight; there's no clean link between what the field asked for and what the office bought, so job costs drift; and when an invoice arrives, no one can confirm it matches a real, approved need.
Keeping requisitions and purchase orders as distinct, connected steps is what gives you both speed and control—the field gets what it needs fast, and the office keeps a defensible record of every commitment. Connecting that whole chain is the job of dedicated construction materials management software, which keeps the request, the approval, and the order linked to the same job from start to finish.
Turn Field Requests Into Controlled Spending
The gap between "we need it" and "we bought it" is where margin quietly leaks. When every field requisition flows into an approved purchase order—tied to the right job the whole way—your procurement stops being a guessing game.
Ready to connect the field to the office? Discover mJob's Materials Management solution today.
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