Best purchase order software for small UK businesses that buy on jobs

In short

Accounting-led tools raise purchase orders well, but a business that buys against customer jobs needs the order to carry the job, margin and delivery. Decide whether purchasing is a finance or an operations task, then test with one real job.

If you are a small UK business choosing purchase order software, the shortlist is short. Your accounting package (Xero is the example here) raises and sends orders and turns them into bills. A finance-led system such as Sage Intacct adds approval workflows and budget control. Zigaflow raises purchase orders from the customer job, carries the supplier cost onto the job margin, and tracks the delivery. If you buy stock for shelves, the first two are enough. If you buy against customer jobs, the question is whether purchasing is a finance task or an operations one.

Two kinds of buyer, two kinds of purchase order

A stock buyer orders to a reorder level. The purchase order only has to be right in itself: correct supplier, quantities and price, then a bill when the invoice arrives. Nothing outside the purchase order depends on it.

A business that buys on jobs works the other way round. A customer accepts a quote, and that acceptance creates a list of things to buy from several suppliers. Each order exists because of that job. The questions that matter sit outside the document: what did this buy do to the job margin, and when will the goods arrive so we can promise a date? A purchase order that cannot answer them is a record of spend, not a tool for managing the job.

That is the thesis of this guide. Stand-alone purchase order tools and accounting add-ons raise an order well. A job-based buyer needs the order to carry the job, the margin and the delivery.

What accounting-led options do well

Xero's UK purchase order page describes customizable layouts and your own numbering, orders built from templates and emailed as PDFs, and user roles that control who can create, approve and send. It shows each order as sent, filled, billed or unfilled, with notes and expected arrival dates, and converts an approved order into a bill to pay. It also says an order can become an invoice when you are on-selling. See the Xero integration page for how Zigaflow works alongside it.

For a business whose purchasing is mostly overheads, materials from one or two regular suppliers, or stock, that is a sound answer. Orders and bills sit next to the bank feed and the ledger, which is where a finance person wants them. At the other end, Sage's UK page for Sage Intacct describes purchase order software within its accounting product, with predefined approval workflows and budget versus actuals reporting. It publishes no price on that page, and it is aimed at finance teams that want control of the procure-to-pay cycle.

Both options start from finance. The purchase order is a ledger event first, and a job is something you may be able to tag it to.

Where job-based buyers feel the gap

The gap shows up in three places.

Raising the order. After a win, someone retypes the job lines into purchase orders, looks up the supplier and copies quantities across. With ten lines across four suppliers, that is four orders built by hand, each a chance for a typo. In Zigaflow you multi-select the lines on the job or sales order, set a supplier against each, and it creates one purchase order per supplier in one action, with the link back to the job kept on both documents. You can also raise one purchase order across several customers' jobs to reach a supplier's minimum order value, per the Zigaflow help center.

Margin. The cost you quoted is a forecast. The cost on the purchase order is the real one. Zigaflow carries the supplier cost onto the job line, so job cost and margin move as you buy, rather than after the supplier invoice is booked. For the mechanics, see purchase orders.

Delivery. A sent purchase order tells you nothing about what the supplier is doing with it. Zigaflow suppliers can acknowledge the order and enter dispatch and tracking details on their own page, and each action moves the PO status. Part and full receipts are booked against the order with the supplier's delivery note number, and the expected date per line shows on the linked job. The person answering the customer's call sees the date without phoning anyone.

Matching the supplier invoice

Weeks after delivery, the supplier invoice arrives and someone has to say whether it matches what you ordered. In Zigaflow, you drop the invoice PDF into Reconciliations, it reads the PDF, finds the PO number and compares the gross value. Where the values differ, you choose which stands, and the PDF is attached to the PO either way. The approved invoice then exports to Xero, QuickBooks or FreeAgent. The detail is on the supplier invoices page.

If you keep Xero for the books, this split is common: operations raise, receive and match in Zigaflow, and finance keeps the ledger.

What Zigaflow does not do, and what it costs

Zigaflow is not an accounting package. It does not replace your ledger, bank feed or VAT return, and it is not a full finance suite. It sits between a CRM and an ERP. If you want one system that is mainly about accounts, use the accounting product.

On price, the Zigaflow pricing page lists purchase orders on every plan, at the time of reading. Essentials is £79 a month with one user included and £69 for each extra user, Go is £199 with two included and £79 extra, and Momentum is £399 with three included and £89 extra. Prices are excluding tax. All plans include a free one-hour onboarding session. Xero publishes its own plan prices on its site, so compare like for like with the number of users you need. Sage Intacct shows no public price on the page I read.

How to decide

Ask one question: who needs to see a purchase order first? If the answer is the person who keeps the books, start with the accounting package. If it is the person who promises dates to customers and watches job margin, start with a job-based system and keep the accounting package for the ledger. Then test it with one real job: raise every purchase order from it, receive a part delivery, and match one invoice. If you can answer "what is this job's margin now and when will the last item arrive" without opening a second system, you have found the right fit.

Sources

• Purchase Order Software | Xero UKXero · accessed 2026-11-03
• Sage Intacct Cloud Based Purchase Order System SoftwareSage · accessed 2026-11-03
• PricingZigaflow · accessed 2026-11-03
• Purchase order software for small businessZigaflow · accessed 2026-11-03
• Creating a purchase order from a job/sales orderZigaflow help center · accessed 2026-11-03