Accounts payable automation, step by step, for UK finance teams

Most guides to accounts payable automation that rank today are written by software vendors, some for American readers. This one is for a UK finance lead: the process step by step, what each kind of tool automates, the controls that stay with people, and the UK rules that shape the design.

We build business automation and integrations with accounting systems, but for many businesses the honest answer is a product you can buy. We say where.

The accounts payable process, step by step

Before choosing a tool, map today's process with the people who run it; our guide to process mapping shows how. We split it into seven steps.

1. Receipt. Invoices arrive as PDFs in a shared inbox, on paper, through supplier portals or as data files. Record the date each arrived: for payment practices reporting, receipt of invoice is when the business receives it, not the date it is entered on to its software.
2. Capture. Someone or something reads the supplier, invoice number, date, net, VAT and total, and sometimes every line. This is where intelligent document processing does its work. It is also the moment to check the document is a real invoice: HMRC says you cannot reclaim VAT using an invalid invoice, a pro-forma invoice, a statement or a delivery note.
3. Coding. Each invoice gets a nominal code, a VAT code and often a cost centre or project. Many suppliers are coded the same way every time, so rules handle the bulk.
4. Matching. Where you raise purchase orders, the invoice is checked against the order (a two-way match) and against what was received (a three-way match), within a tolerance you set. The goods received record often lives in a stock or job system, not the accounts package, and that is where matching often breaks down.
5. Approval. The invoice goes to whoever can approve that amount against that budget, with a reminder if it sits.
6. Payment run. On a set day, someone selects what is due and builds a payment file, and a second person releases it at the bank.
7. Supplier statements. Each month, statements are checked against the ledger to find missing invoices, unapplied credit notes and duplicates.

What each kind of tool automates

Your accounting system's own capture

Start with what you already pay for. In Xero you forward or upload bills, and "Xero's AI extracts the key details to create draft bills ready for approval". Its bills page also lists approval roles, duplicate bill flagging, a payment file for your online banking, and Confirmation of Payee where your bank has enabled it. As of October 2026, Xero's pricing page lists "Enter 10 bills" on Ignite at £18 a month, and automated bill entry from Grow at £39 a month, excluding VAT, after a discounted first six months. On another package, look for the same four things: capture, approval roles, duplicate checks and a payment file.

Dedicated capture and approval tools

Dext takes invoices from a phone, a forwarded email, WhatsApp or a desktop folder, applies the rules it picks up for each supplier, flags duplicates, and sends anything it is unsure of to a person. Test it on a month of your own invoices first. As of October 2026, Dext's business plans start at £290 a year, billed annually and excluding VAT, for 250 documents a month and five users. Line item extraction and supplier statement checks are add-ons, each from £16.50 a month.

ApprovalMax adds multi-level approvals for bills and purchase orders in Xero, QuickBooks Online and NetSuite. Its bill-to-PO matching, on the Advanced and Premium plans, links bills to purchase orders and sends unmatched ones for review. It labels any document approved or changed directly in the accounting system, so a bill that skipped the workflow shows up, and checks new bills against approved ones for duplicates.

Custom integration

Products struggle when the data they need lives in your own systems: goods received in a warehouse system, job costs in an operations platform, contract rates in a spreadsheet, or invoices that large suppliers send as EDI or CSV files. Custom integration fills that gap: software that pulls receipts from the stock system, matches them to orders and invoices, posts matched bills to the accounts package through its API, and sends each exception to a named person.

It also matters for Making Tax Digital. Where VAT data moves between pieces of software, HMRC's VAT Notice 700/22 requires a digital link: file imports and API transfers count, copy and paste does not.

The controls that must stay

• Segregation of duties. The person who sets up or changes a supplier should not approve its invoices, and whoever approves invoices should not release the payment run. In a small team, that may mean the owner releases every run. Tools can enforce this: ApprovalMax's rules can stop whoever raised a request from approving it, and ApprovalMax Pay, for UK businesses on Xero, sets who can approve payments and who can release funds.
• Supplier bank detail changes. A familiar fraud is a message, apparently from a supplier, saying its bank details have changed. UK Finance's Take Five to Stop Fraud campaign tells businesses to "always question changes in payment information and confirm details directly with suppliers using the contact information you have on file". Make a change its own approval, by someone who does not release payments. Never let automation update bank details from an invoice or email: a capture tool that reads an account number off a PDF should flag a difference, not apply it.
• Confirmation of Payee. Pay.UK describes it as an account name-checking service designed to help reduce misdirected payments. Use it where offered; it does not replace the phone call.
• Exceptions and a log. Every invoice that fails a match, rule or check should reach a named person with the reason, and every automated step should be logged: what was read, which rule applied, who approved, what was paid.

UK rules that shape the design

VAT and Making Tax Digital

HMRC says you must keep VAT records for at least 6 years, including invoices you receive, as originals or electronic copies. Under VAT Notice 700/22, your digital records must hold the time of supply, value and input tax claimed for each supply you receive. If your software scans invoices and keeps an image with all the detail needed for VAT, the notice says you need not keep the paper original, unless it is needed for another purpose. So keep the image your capture tool takes, not only the figures.

E-invoicing from 2029

In its consultation response of 26 November 2025, the government said all VAT invoices must be issued as e-invoices from 2029, and that PDFs, Word files, images and HTML invoices did not count. Its implementation roadmap, published at Budget 2026 on 28 October 2026, says that from 1 April 2029 VAT-registered businesses will need to issue and receive VAT invoices as e-invoices, unless an exemption applies, with Peppol as the core network. Full details of scope are due 12 to 18 months before. The capture tools above read PDFs and photos; from 2029, invoices from VAT-registered suppliers should arrive as data instead. Ask any vendor how it will receive e-invoices, and be wary of long contracts that ignore the question.

Payment practices reporting

Companies and LLPs that exceeded two or all three of the thresholds (£54 million turnover, £27 million balance sheet total, 250 employees) on their last two balance sheet dates must report on their payment practices on a government web service, normally twice a year, within 30 days of the end of each reporting period. The figures include average days to pay from receipt of invoice, the share paid in 30 days or fewer, 31 to 60 days and 61 days or more, and the share not paid within agreed terms. For financial years starting on or after 1 January 2025, they include the share not paid within terms because of a dispute. From financial years starting on or after 1 April 2025, reports also state whether any qualifying construction contracts include retention clauses, with more detail where they do. So record the received date on every invoice, and every dispute, and the report becomes a query, not a project.

StoreBay: the other side of the ledger

StoreBay, the self-storage platform we built and run, sits on the receivables side: it invoices each plan on its renewal date from its own records and collects by card or Direct Debit, so nothing is read off a page. Accounts payable is the mirror image: every supplier has its own layout, which is why capture needs the most checking.

One StoreBay decision carries straight across to a payment run. Calling a payment provider directly from the code risks a charge with no record, or a record with no charge, if anything fails between the two. So any StoreBay change that owes the outside world something writes that instruction in the same database transaction. Separate workers carry it out with retries and duplicate protection, and an instruction that keeps failing raises an alert. Software that pays suppliers needs the same guarantee: no payment without a record, no record without a payment, and no invoice paid twice because a file was uploaded twice.

When building is worth it

For most small and mid-sized businesses on Xero or QuickBooks, the order is: the accounting system's own capture first, a capture tool when volume or line items demand it, and an approval tool when you need purchase orders, several approvers or a fuller audit trail. Buying is usually quicker and cheaper than building, and the vendor keeps up with the accounting system.

Build when what decides whether to pay sits where those products cannot see it, as above, or when several entities need one process. Even then, build the integration, not a new ledger: keep the accounting system as the record and write software only for the gap. AI helps most with reading invoices in many layouts; our guide to AI in finance covers what it can be trusted with.

If you want a hand

If the gap is between your own systems and your accounts, that is work we do. Start a project and tell us how invoices reach you today.