What is a purchase order approval workflow?
Quick answer
A PO approval workflow is the set of steps a purchase order must pass before it is sent to a vendor. Rules decide who approves based on amount, department or category, so small orders move quickly and larger ones get a manager's or finance's sign-off. Each approval is recorded for later review.
Last updated
Updated · By Robert Breen
Why it matters for a small business
Once a PO goes out, the business has committed money. The approval workflow is the last chance to ask whether this purchase is needed, budgeted and priced right. Without one, approvals happen in hallway conversations and nobody can say later who agreed to what.
Good workflows are simple. A common pattern is tiers by amount, such as under $500 approved by the requester's manager and above that by the owner or finance, though the numbers are yours to pick. It usually starts from a purchase requisition and is one kind of approval workflow. The records it leaves also support invoice approval when the bill arrives.
In a real lesson: Build an Expense Reimbursement Form With AI Policy Checks
Stepthrough has no lesson that approves purchase orders. The AI Expense Reimbursement Form lesson builds the same routing logic for a different document. Maple Street Bookkeeping, a made-up firm, gets a Lovable form that sends each request to an n8n webhook, where an AI agent picks a status.
The rule that matters here is the dollar tier: "Needs manager OK: the amount is $100 or more." Swap reimbursement requests for POs and that one line becomes the heart of a PO workflow: below the line it moves on, above it waits for a person. The agent then saves the request to an Expense Requests sheet and emails the status, which gives you a record of every decision.
In a real PO workflow, keep the AI to sorting and notifying. The approval itself should be a named person clicking yes, not the model.
Try this lesson free or read the step-by-step guide.
Common confusions
PO approval vs requisition approval
A requisition approval says yes to the need inside the company. A PO approval says yes to the specific order, vendor and price going out. Small businesses often combine them into one step.
PO approval vs invoice approval
PO approval happens before the order is placed. Invoice approval happens after the bill arrives and confirms it should be paid.
Tips
- Write the dollar tiers down and keep them few, two or three at most.
- Name a backup approver so orders do not stall when someone is out.
- Have the workflow send the requester a status message at every step.
- Let automation route and remind, and keep the final yes with a person.
Related terms
More Business terms
Where you use it: free lessons
- Build an Expense Reimbursement Form With AI Policy Checks (Lovable and n8n, 15 min)
- Build an AI Maintenance and IT Request Form (Lovable and n8n, 15 min)
More free tutorials
Frequently asked questions
- Who approves a purchase order?
- It depends on your policy. Often the requester's manager approves smaller orders and the owner or finance approves larger ones. Write down who approves what so there is no guessing.
- Can AI approve purchase orders?
- AI can check a PO against your rules, route it and send reminders. The decision to commit money should stay with a person who has authority, with the approval recorded.
- What should a PO approval policy include?
- Dollar thresholds and who approves at each level, which purchases need a PO at all, a backup approver, and how approvals are recorded so you can find them when the invoice arrives.