Table of Content
What is the purchase order process?
The purchase order process is the sequence a company follows to buy goods or services: someone raises a purchase requisition, a manager approves it, buying creates and sends a purchase order (PO) to the supplier, the supplier confirms, the goods are received and checked, the supplier invoice is matched to the PO and the receipt, and finance pays. Nine steps cover it, and most of them can be automated.
The short version
- A PO is a promise to pay. A purchase requisition is only a request to buy. Mixing them up is the most common source of confusion.
- Nine steps, three controls. Approval before you commit, receipt before you pay and a three-way match before you release money.
- Automate the routing, not the judgment. Software can route approvals, build the PO, send it and match the invoice. People handle exceptions and supplier relationships.
- Match type matters. Two-way matching compares PO and invoice. Three-way matching adds the goods receipt and catches paying for items that never arrived.
- Start with the PO-to-invoice leg. It is where errors and late payments pile up, and where automation pays back first.
- Need it built into your ERP? Our Odoo development services and AI automation teams automate purchasing end to end.
What a purchase order is, and what it is not
A purchase order is a document the buyer sends to a supplier. It lists what you want, the quantity, the agreed price, delivery terms and payment terms. Once the supplier accepts it, it becomes a legal commitment. That is why companies put approvals in front of it.
It helps to separate four documents that people mix up:
| Document | Who creates it | What it means | When |
|---|---|---|---|
| Purchase requisition | The employee who needs something | A request to buy. It commits no money. | Before approval |
| Purchase order | Purchasing, from an approved requisition | A commitment to buy at agreed terms | After approval |
| Goods receipt | Warehouse or the requester | Proof that the items or service arrived | On delivery |
| Supplier invoice | The supplier | A demand for payment | After delivery |
If you are still deciding between a PO-based process and card or petty-cash buying, use a simple rule. Use a PO for anything that is above your approval threshold, repeated or involves a supplier you cannot easily change. Low-value, one-off buys can skip it if your policy says so.
9 purchase order process steps you can automate
Each step lists what happens, what to automate and the mistake to avoid. The same flow works in an ERP, a procurement tool or a custom system.
1. Raise a purchase requisition
What happens: An employee requests an item or service with a description, quantity, estimated cost, cost center and needed-by date.
Automate: A form or chat request that pulls approved catalog items and suppliers, fills the cost center from the requester’s profile and checks budget.
Choose it if people email requests or use spreadsheets. Watch for free-text requests. They cause wrong items, missing budget codes and rework.
2. Approve the requisition
What happens: A budget owner or manager approves or rejects. Higher amounts need more approvers.
Automate: Approval routing by amount, department and category, with reminders and automatic escalation. This is the purchase order approval workflow, and it is the biggest time saver in the process.
Choose it if approvals wait in inboxes. Watch for a single approver for everything. Use limits so small buys move fast and large ones get review.
3. Choose the supplier and confirm the price
What happens: Buying picks a supplier from the approved list or gets quotes for larger purchases.
Automate: Preferred supplier suggestions, contract price lookup and quote requests sent to several suppliers at once.
Choose it if you buy the same things repeatedly. Watch for off-contract buying. Show the contract price at the point of request.
4. Create the purchase order
What happens: Buying creates the PO from the approved requisition, with a unique PO number, line items, price, delivery date and terms.
Automate: Generate the PO automatically from the approved requisition and copy over accounts and tax codes. People review only the exceptions.
Choose it if purchasing re-keys approved requests. Watch for editing the PO after sending it. Use change orders so the record stays clear.
5. Send the PO to the supplier
What happens: The PO goes to the supplier by email, a supplier portal or an electronic exchange.
Automate: Send it from the system with a PDF and a link, and log the time sent.
Choose it if suppliers say they never got the order. Watch for sending from personal inboxes. You lose the audit trail.
6. Get supplier acknowledgment
What happens: The supplier confirms price, quantity and delivery date, or proposes changes.
Automate: Capture confirmations by link or email parsing, flag any difference from the PO and chase suppliers who have not replied.
Choose it if delivery dates matter. Watch for silent acceptance. Without a confirmation, a dispute later is hard to settle.
7. Receive and inspect the goods
What happens: The warehouse or requester checks the delivery against the PO and records a goods receipt, including partial deliveries and damaged items.
Automate: Scan barcodes or tap a mobile screen to receive against the PO, and update stock levels at once. Our guide to ecommerce inventory management shows how receipts feed stock accuracy.
Choose it if you stock physical goods. Watch for receiving without the PO. You cannot match it later.
8. Match the invoice (two-way or three-way)
What happens: Accounts payable compares the supplier invoice with the PO and, for three-way matching, with the goods receipt. If quantity, price and totals agree within a set tolerance, the invoice passes.
Automate: Extract invoice data, match it to the PO and receipt, approve clean matches automatically and send mismatches to a queue with the reason. Our guide to invoice processing automation walks through this step in detail.
Choose it if volume is high or errors are costly. Watch for tolerances that are too loose. They hide overbilling.
9. Pay the supplier and close the PO
What happens: Finance schedules the payment, records it and closes the PO when everything is received and paid.
Automate: Schedule payments to capture early-pay discounts, post to the ledger and close completed POs. Our guides to payment reconciliation automation and cash flow forecasting cover what happens next.
Choose it if you want to avoid late fees and missed discounts. Watch for leaving POs open. Old open commitments distort your budget.
Two-way vs three-way matching
Matching is the control that protects you from paying wrong or fraudulent invoices. Choose the level by risk and value.
| Match type | What it compares | Catches | Best for |
|---|---|---|---|
| Two-way | PO and invoice | Price and quantity differences between order and bill | Services and low-risk purchases |
| Three-way | PO, goods receipt and invoice | Paying for goods that never arrived or arrived short | Physical goods and higher values |
| Four-way | Adds inspection or acceptance | Items that arrived but failed quality checks | Regulated or high-risk goods |
A tolerance is the allowed difference before an invoice is held, for example a small percentage on price or a set amount on quantity. Set tolerances by category and review the exceptions each month.
Purchase order software: what it should do
Searches for purchase order software, purchase order systems and purchase order management software return a mix of accounting tools, procurement platforms and ERPs. Pick by the problem you need to solve.
| Option | Best for | Watch for |
|---|---|---|
| Accounting software with PO features | Small businesses with simple buying | Limited approval rules and receiving |
| Procurement platforms | Teams with many suppliers, catalogs and approvals | Extra integration with your ERP and accounting system |
| ERP purchasing modules | Companies that need stock, finance and purchasing in one place | Implementation effort and configuration |
| Custom workflow or agent | Unusual approval chains or legacy systems | Needs an owner and ongoing maintenance |
Whatever you choose, look for these features:
- Rule-based approvals by amount, category, department and budget.
- Budget checks at the requisition stage, not after the order.
- Supplier and catalog management, with contract prices.
- Goods receipt, including partial deliveries and returns.
- Matching with tolerances and an exception queue.
- Purchase order tracking that shows status from request to payment.
- Integration with your accounting or ERP, so ledgers update on their own.
If you are weighing ERP options, our guides to ERP system examples, NetSuite consulting and Odoo development companies explain what each includes. For a wider look at how AI changes purchasing inside an ERP, see AI agents in ERP.
Purchase order automation: what an AI agent adds
Rules handle the predictable cases. An agent helps with the messy ones. In purchasing, a good agent can read a free-text request and suggest the right catalog item, draft a request for quotes, compare supplier replies, flag an unusual price against past orders and explain why an invoice failed its match. It should recommend, not approve, until you trust it.
A safe rollout is to start with read-only help, move to drafting with human approval and only then allow small automatic actions within limits. Our guide to business process mapping examples helps you document the current flow before you automate it, and our guide to AI workflow automation tools compares platforms.
Metrics that show whether the process works
| Metric | Formula | Why it matters |
|---|---|---|
| Requisition-to-PO cycle time | Average days from approved requisition to PO sent | Shows delays in buying |
| Approval time | Average hours from request to final approval | Shows approver bottlenecks |
| PO accuracy | POs with no later change / total POs | Shows quality of the request |
| Touchless match rate | Invoices matched with no manual work / total invoices | Shows how much automation is working |
| Exception rate | Invoices held in the match queue / total invoices | Points to supplier or process problems |
| On-time payment rate | Invoices paid by due date / total invoices | Shows supplier trust and discount capture |
| Spend under contract | Spend with contract pricing / total spend | Shows compliance |
7 purchase order mistakes to avoid
- Buying first and raising the PO afterward. The commitment is made before the control.
- Skipping the receipt. You lose three-way matching and cannot prove delivery.
- Letting one person raise, approve and pay. Split these duties.
- Using email as the system of record. Search is slow and the trail is incomplete.
- Overly complex approvals. People find workarounds when rules slow them down.
- Ignoring blanket orders. Recurring buys from one supplier need a standing PO with a limit.
- Automating a broken process. Fix the flow first, then speed it up.
How to start in 5 steps
- Map the current flow, from request to payment, and mark each place where someone retypes data.
- Set approval limits and who covers when an approver is away.
- Clean supplier and item data, so requests and POs use the same codes. See our guide to data migration tools if you are moving systems.
- Automate the PO-to-invoice leg first, with matching and an exception queue.
- Measure the seven metrics above monthly and tune tolerances and approvals.
Frequently Asked Questions
What is the purchase order process?
It is the set of steps a company follows to buy: raise a requisition, approve it, create and send the PO, get supplier confirmation, receive the goods, match the invoice and pay. Each step creates a record that supports audit and budget control.
What is the difference between a purchase requisition and a purchase order?
A requisition is an internal request to buy and commits no money. A purchase order is sent to the supplier after approval and creates a binding commitment. The requisition usually becomes the PO once it is approved.
What happens after a purchase order is issued?
The supplier acknowledges it and delivers. The buyer records a goods receipt, accounts payable matches the invoice to the PO and receipt, and finance pays. The PO then closes when it is fully received and paid.
Who prepares a purchase order?
Usually the purchasing or procurement team prepares it from an approved requisition. In small companies the manager or owner may do it. The requester should not create, approve and pay for the same order.
Does a purchase order mean the invoice has been paid?
No. A PO is a commitment to buy, not a payment. Payment happens after the supplier invoice is received, matched and approved, and it is recorded separately.
When should you not use a purchase order?
Many companies skip POs for small, one-off or recurring items such as utilities, subscriptions and low-value card purchases, based on a written threshold. Anything above the threshold or with a new supplier should have one.
What is three-way matching?
Three-way matching compares the purchase order, the goods receipt and the supplier invoice. If quantity, price and totals agree within tolerance, the invoice can be paid. It stops you paying for goods that were never delivered.
Can the purchase order process be fully automated?
Most of it can. Routing, PO creation, sending, matching and payment scheduling are good candidates. People should still handle new suppliers, disputes and exceptions, and set the rules that the automation follows.
What is the best purchase order software for a small business?
Start with the purchasing features in your accounting software if buying is simple. Move to a procurement tool or ERP module when you need multi-level approvals, receiving and matching. Compare approvals, integrations and pricing as you grow.
How do you track a purchase order?
Use a status field in your system that moves from requested to approved, sent, acknowledged, received, invoiced, paid and closed. Dashboards and alerts then show late deliveries and POs waiting for approval.
Bottom Line
A good purchase order process puts three controls in the right order: approval before commitment, receipt before payment and matching before release of funds. Automate the routing and matching first, keep people on exceptions and measure cycle time and touchless match rate.
If you want it built into your ERP or workflow tools, explore our Odoo development services or our AI automation team.
