Purchase Order Software: How to Choose One
Ivan de Ramon · NOV 7, 2026
Purchase order software helps you create, send, approve and track orders to your suppliers. For a distributor, the best choice is the one that also knows your stock, your sales and your supplier lead times, because the hard part of a purchase order is not the document. It is deciding what to buy and how much.
This guide explains the three kinds of purchase order software, what to check before you buy, and how a good purchase order process looks in a company with 10 to 200 people.
What does purchase order software do?
A purchase order (PO) is your written request to a supplier: these items, this quantity, this price, delivered by this date. Software does five jobs around it:
- Create. Build the PO from a supplier, items and quantities. Reuse past orders.
- Approve. Send it to a manager if it is over a set amount.
- Send. Email or transmit it to the supplier.
- Track. Show what is still open, what is late and what was partly delivered.
- Receive and match. Record what arrived. Compare it to the PO and to the supplier invoice.
Some tools do only the middle three. Others also tell you what to buy in the first place. That difference matters most for a distributor.
The three kinds of purchase order software
| Kind | Examples of the category | Good at | Weak at |
|---|---|---|---|
| Accounting software with POs | QuickBooks Online, Xero | Simple POs, bills, one place for money | Knowing what to buy, partial receipts, many suppliers |
| Procurement and spend tools | Procurement platforms for approvals and budgets | Approval chains, budgets, spend control, indirect purchases | Resale inventory, stock levels, demand |
| Inventory and ERP systems | Inventory management for distributors | POs tied to stock, forecast, lead times and receiving | Heavy spend controls for office supplies |
Check each vendor's own plan page for what a plan includes. For example, whether purchase orders sit in a lower or higher accounting plan changes the price you pay.
Which kind fits a distributor?
You buy things to resell. Your purchase decision depends on stock on hand, open customer orders, orders already on the way and how fast the item sells. A tool that only builds the document leaves that work in a spreadsheet. A procurement tool is built for buying things the company uses, not things it sells.
For most distributors, the PO must live next to the inventory records.
Why the "what to buy" part matters more than the document
Look at one item. Your system says 40 on hand. That is not enough to decide.
| Measure | Units |
|---|---|
| On hand | 40 |
| Reserved for open customer orders | 25 |
| Available to sell | 15 |
| Already on order from the supplier | 60 |
| Expected sales in the supplier lead time | 70 |
Position after lead time: 15 + 60 - 70 = 5 units. That is thin but not empty. If you only looked at "40 on hand," you might order too much. If you only looked at "15 available," you might order again and double up on the 60 already coming. A PO tool that sees all five numbers helps you buy the right amount.
Now add real supplier rules. The supplier sells in cases of 12 and has a minimum order of 5 cases (60 units). The buyer needs 40 more units to be safe. The order must be 60. Good software shows this clearly, so the buyer can decide: order 60, or wait for the next combined order.
What to check before you buy
Use this checklist in your demo. Ask the vendor to show each one with your data, not slides.
Creating the order
- Can I build a PO from a suggested buy list, grouped by supplier?
- Does it respect supplier minimum order quantities, case packs and units of measure?
- Can I copy a past PO?
- Can I order the same item from two suppliers with different costs and lead times?
Controls
- Can I set approval rules, such as "over $5,000 needs the owner"?
- Who can create, edit and send a PO? Can I limit it by role?
- Is there a record of who changed what?
Tracking and receiving
- Can I receive part of a PO and keep the rest open?
- Does the received quantity update stock right away?
- Can I see late POs and the customer orders waiting on them?
- Can I record freight and extra costs against the order, so my item cost is right?
Connections
- Does it connect to my accounting system, so bills match POs?
- Does it connect to my sales channels, so open orders reduce available stock?
- Can I export every PO and supplier record if I leave?
Cost
- Is the price per user, per PO, or per company?
- What does implementation cost? Who does the data work?
- What do the add-ons you need cost?
Ask for the all-in monthly number for your team size before you compare tools. Our guide to inventory management software pricing shows why sticker prices mislead.
Three-way match in plain words
Three-way match means checking three papers before you pay:
- The purchase order: what you asked for.
- The receiving record: what arrived.
- The supplier invoice: what they ask you to pay.
If all three agree, pay. If not, find out why. Common differences: the supplier shipped 90 of 100, the price changed, or freight was added. A small company can do this by eye on a few POs. At 50 POs a week you need the software to flag the differences.
A realistic process for a 20-person distributor
- Monday: The buyer opens the list of items that need attention. The list shows available stock, open POs and forecast demand.
- Monday: The buyer adjusts quantities for what the data cannot know, such as a promotion or a customer leaving.
- Monday: The system creates PO drafts grouped by supplier.
- Tuesday: A manager approves anything over the limit. POs go out.
- During the week: The warehouse receives against the PO. Partial deliveries leave the rest open.
- Weekly: The buyer checks late POs and calls the supplier.
- Monthly: Review supplier lead times. Are they what you assumed? If not, update them.
The Inventory Playbook has more on scheduled buys and min/max if you want to choose a method for step 1.
PO statuses worth tracking
A PO should always have a clear status, so anyone can tell where it stands:
| Status | Meaning | What to do |
|---|---|---|
| Draft | Prepared, not approved | Buyer reviews quantities |
| Approved | Allowed to go out | Send to the supplier |
| Sent | Supplier has it | Wait for confirmation |
| Confirmed | Supplier agreed on date and price | Update the expected date |
| Partly received | Some lines arrived | Keep the rest open |
| Closed | All received and matched | Pay the invoice |
Drafts and sent orders should not look the same in your reports. A draft is only an idea. Only sent and confirmed orders belong in "on order."
Mistakes to avoid
- Treating a PO as a guarantee of stock. An open PO is not received inventory. Count it as "on order," not "on hand."
- Ordering by feeling. Without numbers, the loudest customer decides what you buy.
- No supplier lead time data. If lead times are guesses, every order quantity is a guess.
- Letting the system send orders unreviewed on day one. Start with drafts that a person approves.
- Ignoring freight. If landed cost is not on the PO, your margin reports are wrong.
How Convexity handles purchase orders
Convexity is inventory software for small and mid-size distributors. These facts come from our product pages:
- Convexity shows suggested purchase quantities by supplier, next to stock, demand and supplier context. You can adjust the quantity before you act.
- You can turn on automatic draft creation. Convexity then prepares purchase order drafts from the recommendations. Your buyer reviews quantities and supplier details before approval. A draft is not an order sent to a supplier.
- Stock is shown as on hand, reserved, available and on order. On-order counts open warehouse-stock purchase orders, minus what you already received. Draft and factory-direct purchase orders are not part of that warehouse total.
- Whether an approved order is written back into another ERP depends on your setup. We agree that with you and test it first.
- Convexity keeps QuickBooks Online as the accounting system.
You can see the buying flow on the inventory optimization software page. A Land Rover parts distributor describes how its buyers use it in the Rovers North story.
Frequently asked questions
What is purchase order software?
It is software that creates, approves, sends and tracks purchase orders to suppliers, and records what you receive. Some versions also use stock and demand data to suggest what to order.
Do I need purchase order software, or is accounting software enough?
Accounting software can handle simple POs for a few suppliers. If you order many SKUs, receive partial shipments, use supplier minimums or need to know what is already on order, you need a tool tied to inventory.
What is the difference between purchase order software and procurement software?
Procurement software focuses on spend control: budgets, approvals and vendor management, often for things a company uses. Purchase order software for distributors focuses on buying goods to resell, so it needs stock levels, lead times and demand.
How much does purchase order software cost?
It depends on the kind. PO features inside accounting plans are priced within those plans. Procurement tools and inventory systems have their own plans. Ask each vendor for an all-in monthly figure for your number of users, plus implementation.