A Purchase Order Process for a Small Business: From Request to Payment in Five Steps

A restaurant's chef orders vegetables by voice message every evening. The owner's brother orders packaging when it looks low. The manager orders cleaning supplies from whoever calls. At the end of the month, invoices arrive from eleven suppliers. Nobody can say whether the quantities are right, whether the prices are what was agreed, or whether one of them was already paid by transfer two weeks ago. The business has purchasing, but it has no purchase order process.

What goes wrong without one

• Overpaying. The invoice shows a higher price than was quoted, and nobody has the quote.
• Paying for what did not arrive. Twenty cartons billed, eighteen delivered.
• Paying twice. Once from the delivery note, once from the monthly statement.
• Buying what was not needed. Two people order the same thing.
• No commitment view. The owner cannot see what has been ordered and not yet billed, so cash planning is guesswork.
• Opportunity for fraud. One person can order, receive and approve payment with no second pair of eyes.

A simple process closes all of these.

The five steps

1. Request

Someone identifies a need and writes it down: what, how many, by when, and why. For regular stock this can be a reorder list. For anything else, a short request.

This step separates "we need" from "we buy". It lets someone ask whether the item is already in stock or already on order.

2. Approval

A person with authority approves the request before anything is ordered.

Approval limits keep this fast:

Set the thresholds to suit your business. The aim is that most purchases are approved by someone close to the work, within the hour, and the owner sees only the significant ones.

3. Purchase order

The approved request becomes a purchase order sent to the supplier. It states:

• A PO number.
• Date.
• Supplier.
• Items, with description, quantity, unit and agreed price.
• Total.
• Delivery date and place.
• Payment terms.
• Who ordered and who approved.

Send it by email or message, as a document. Ask the supplier to confirm, and to quote the PO number on the delivery note and invoice.

The PO is a commitment. From this moment the business knows it will owe this amount, which is what makes cash planning possible.

4. Receipt

When goods arrive, someone checks them against the purchase order, not against the supplier's delivery note alone.

• Count what actually arrived.
• Check quality and condition.
• Record what was received, with the date and the PO number. This is the goods received note.
• Note shortages, damage and substitutions on the supplier's delivery note before signing it, and keep a copy.

Where possible, the person who receives is not the person who ordered. For services, the equivalent is confirmation by the person who asked for the work that it was done.

5. Invoice match and payment

When the invoice arrives, compare three documents:

• Purchase order: what was ordered and at what price.
• Goods received note: what arrived.
• Invoice: what the supplier is billing.

This is the three-way match. Pay when all three agree. When they do not:

• Quantity billed exceeds quantity received: pay for what arrived, or hold the invoice and ask for a credit note.
• Price is higher than the PO: query it. Pay the PO price unless a change was approved.
• Items not on the PO: who ordered them?
• No PO at all: find out who bought, and why outside the process.

Then pay according to the terms, mark the invoice paid with the payment reference, and file the three documents together.

Preventing double payment

• Pay only against invoices, not delivery notes or statements.
• Record each invoice once, with the supplier's invoice number. A second entry with the same supplier and number is refused.
• Mark paid invoices clearly.
• Reconcile supplier statements monthly against your records.

Separation of duties

The principle: no single person should be able to order, receive and pay.

In a business of five people, perfect separation is impossible. Do what you can:

• The person who orders is not the one who approves payment.
• The owner approves all payments above a threshold, with the three documents attached.
• The owner looks at the bank statement and the list of payments every week.
• New suppliers and changes to supplier bank details are confirmed by the owner, by calling a known number. Fraud by fake bank-detail changes is common and costly.

Standing orders and regular purchases

Daily vegetable orders do not each need an approval.

• Agree a price list with the supplier for a period.
• Set a standing approval for orders within a daily or weekly limit.
• Still record each order and each receipt. The chef's voice message becomes a short written order, and the delivery is checked on arrival.
• Match the weekly or monthly invoice against the orders and receipts for the period.

The process flexes. The record of what was ordered and what arrived does not.

Choosing suppliers

For significant or repeated purchases:

• Get more than one quote, at least occasionally. Prices drift when nobody compares.
• Compare total cost: price, delivery, minimum quantity, payment terms, reliability.
• Keep a supplier list with agreed prices and terms.
• Review yearly.

What to keep on record

For each purchase: the request, the approval, the PO, the supplier's confirmation, the goods received note, the invoice and the payment proof. Filed by PO number, on paper or digitally. When a question arises six months later, the answer takes one minute.

What to measure

• Purchases without a PO, by value. This should fall toward zero.
• Invoices that failed the match, and why.
• Open POs: ordered and not yet received, and received and not yet billed. This is money you are committed to.
• Price changes by item over time.
• Supplier performance: on-time, complete, correct.

Introducing it without resistance

• Start with stock and anything above the threshold. Leave small purchases alone.
• Make the PO easy: a template with supplier and usual items filled in.
• Tell suppliers. "From next month, invoices need our PO number to be paid." Suppliers adapt quickly when payment depends on it.
• Explain why to staff. It is not about distrust. It is so that the business pays the right amount once.
• Hold the line. The first invoice paid without a PO, "just this once", ends the process.

Common mistakes

• Orders by phone with nothing written.
• Signing delivery notes without counting.
• Paying from statements.
• The same person ordering, receiving and paying.
• A process so heavy that people bypass it.
• Changing supplier bank details on the strength of an email.
• No view of open orders.

Tools

A spreadsheet with numbered POs and a folder per PO is enough to begin. Bookkeeping software that records purchase bills against suppliers makes matching and duplicate checks easier. Polynusa's bookkeeping records supplier bills and payments in one workspace. See the pricing page.

Summary

Separate needing from buying: request, approve within limits, issue a numbered purchase order with agreed prices, check what arrives against the order, and pay only when order, receipt and invoice agree. Keep small purchases outside the process with a threshold, give regular suppliers standing arrangements while still recording orders and receipts, split duties as far as your size allows, and confirm any change of supplier bank details by phone.

FAQ

Does a small business really need purchase orders?

Once more than one person can buy on behalf of the business, or purchases are large enough to matter, yes. A purchase order records what was ordered, at what price and by whom before the goods arrive. Without it there is nothing to check a delivery or an invoice against, and disputes with suppliers become one person's memory against another's.

What is a three-way match?

It is a check made before paying a supplier: the purchase order, the record of what was received and the supplier's invoice must agree on item, quantity and price. If the invoice bills for more than was ordered or received, or at a higher price, it is queried before payment. It is the main defence against overpaying.

Should every small purchase go through the process?

No. Set a threshold below which staff may buy from petty cash or a company card with a receipt. A process that demands a form for a box of pens will be ignored for everything. Apply the full process to stock, equipment, services and anything above the threshold.