Peppol e-invoicing in the UK: a guide for accountants

E-invoicing becomes mandatory in the UK on 1 April 2029. From that date, every VAT-registered business must be able to receive e-invoices. It must also send its VAT invoices to VAT-registered customers and public bodies as e-invoices. Invoices will travel as structured data through the Peppol network, using certified providers called access points. HMRC published its implementation roadmap on 28 October 2026. For accountants, the change means a wave of client questions about software, invoice processes and approval controls. Those questions will arrive in the same years as Making Tax Digital for Income Tax.

Why clients will bring e-invoicing to their accountant first

When UK e-invoicing becomes mandatory in April 2029, most small businesses will not ring HMRC or read the technical standards. They will ask their accountant. That is what happened in Belgium, which made e-invoicing compulsory in January 2026, and it is very likely to happen here.

This piece is for practices that advise clients on tax, bookkeeping and finance systems. It covers how e-invoicing fits into a practice calendar that already includes Making Tax Digital, what Belgian accountants and software providers learned in the past year, the questions clients are likely to ask, and why approval controls deserve a place in those conversations.

HMRC published its implementation roadmap on 28 October 2026. It confirms who is in scope and when the detailed rules will be published. The technical standards will not be final until between October 2027 and April 2028, but most of the preparation work does not depend on them.

For the business-side view, including the full UK timeline and what Italy, France, Germany and Poland have learned so far, read our guide to the UK e-invoicing mandate.

How e-invoicing lands on top of Making Tax Digital for Income Tax

Practices are already dealing with a major change to how personal tax is reported. Making Tax Digital for Income Tax (MTD for Income Tax) requires sole traders and landlords to keep digital records and send HMRC quarterly updates. It is being phased in by income:

So e-invoicing arrives one year after the last MTD for Income Tax group joins. A practice that is onboarding clients to quarterly reporting through 2027 and 2028 will be doing that while the same clients, or their larger business clients, start asking about e-invoicing.

The two changes affect different people. MTD for Income Tax is about sole traders and landlords reporting their own income. E-invoicing applies to VAT invoices, so it reaches every VAT-registered business, including limited companies that MTD for Income Tax does not touch. But both push clients towards the same thing: keeping their records in software rather than on paper or in spreadsheets. A practice that plans the two together can avoid moving a client onto new software for MTD and then moving them again for e-invoicing.

The roadmap links the two in one practical way. HMRC is designing an exemption for people who cannot reasonably use software, for example because of their age, a disability or where they live. It will follow the same approach as the existing exemption from MTD for VAT. Practices that have helped clients apply for an MTD exemption will recognise the process. Details of how to apply for the e-invoicing exemption are due by April 2028.

What Peppol is and how it will work in the UK

Peppol is an international set of rules and a network for sending invoices and other business documents between different software systems. On 23 June 2026, HM Treasury and HMRC confirmed it as the core network for UK e-invoicing. The October 2026 roadmap says the UK will build on existing international standards. HMRC will consult in spring 2027 on the technical standards and on any requirements specific to the UK.

Peppol uses what is called a four-corner model. An invoice passes through four points:

1. The supplier's accounting software creates the invoice.
2. The supplier's access point checks it and sends it across the network.
3. The customer's access point receives it.
4. The customer's accounting software takes it in, ready to approve.

An access point is a certified provider connected to the network. For most small businesses, it will be their accounting software provider or a partner it works with. HMRC will consult in spring 2027 on how access points will be certified in the UK. HMRC will also take over the running of Peppol in the UK from NHS Supply Chain. Each business on the network has a Peppol ID, which tells other access points where to deliver its invoices. A business usually gets its Peppol ID through its access point when it signs up, so clients will rarely need to apply for one themselves. The UK will decide which identifier to use, such as a VAT number or company number, between October 2027 and April 2028.

A practice does not need to become an access point to support clients. What it does need is to know which access points its clients' software uses and how each one is set up.

What Belgium's first year of e-invoicing showed about the accountant's role

Belgium is the closest match to what the UK is planning. Since 1 January 2026, every VAT-registered business in Belgium has had to send and receive structured e-invoices for sales to other businesses, through the Peppol network. Peppol is the same network the UK confirmed in June 2026. Invoices pass between businesses through their chosen software providers, and the tax authority does not approve each one.

The deadline was known two years ahead, and many businesses still left it late

Belgian businesses had roughly two years' notice. Even so, Robin Appeltants of Wolters Kluwer Belgium, whose team supplies small-business software, told Wolters Kluwer that many businesses waited until late 2025 and some expected another delay. Those that started six months to a year early had an easier time. Some late starters had invoices go unpaid, which hit their cash flow.

The government did not delay. It offered a tolerance period from 1 January to 31 March 2026, but only for businesses that could show they had taken reasonable and timely steps to comply. Since 1 April, fines of €1,500, €3,000 and €5,000 apply for a first, second and later offence. By December 2025, KPMG reported that more than half a million businesses had already adopted e-invoicing, with sign-ups speeding up from September 2025.

Some businesses' invoice approval processes stopped working

Appeltants described one problem that will be familiar to anyone who has seen how small businesses handle bills. Some companies printed emailed PDF invoices and passed the paper around for checking and sign-off. When invoices started arriving as structured data through Peppol, there was often nothing to print, and the approval process stopped working.

His team also found that unusual arrangements were more common than expected. They planned for a few customers to need self-billing, where the buyer raises the invoice on the supplier's behalf. In the end, hundreds of customers needed it.

Belgium paid part of the cost, including advice

Belgium gave small businesses and the self-employed an increased tax deduction of 120% on subscription invoicing software for the 2024 to 2027 tax periods. Some Belgian providers report that advice from an accountant or bookkeeper on e-invoicing also qualifies. The government also published a list of more than 350 e-invoicing software providers to help businesses choose.

The UK has not announced any tax relief like Belgium’s. Instead, its roadmap points to free and low-cost e-invoicing products that already exist. It also says several software providers have committed to including e-invoicing in their core package at no extra cost. Belgium also gave businesses a three-month tolerance period, and the UK has not announced one. HMRC plans to base its penalties on the existing penalties for VAT invoice errors, with full details due by April 2028.

Questions clients are likely to ask about UK e-invoicing, with plain answers

The answers below reflect HMRC’s roadmap, published on 28 October 2026. Some details, such as the technical standards, will not be confirmed until between October 2027 and April 2028.

"We already email our invoices. Aren't we doing e-invoicing?" Probably not. A PDF attached to an email does not count. An e-invoice is structured data that the customer's software can read without anyone retyping it. HMRC's own research found that some businesses were confused in the other direction too: a number said they did not use e-invoicing, then described processes that did qualify. It is worth asking clients to show you how an invoice leaves and arrives, rather than asking whether they e-invoice.

"Does this apply to us if we are not VAT registered?" No. A business that is not VAT-registered does not issue VAT invoices, so it is not required to send e-invoices. The roadmap also confirms that sales to customers who are not VAT-registered are out of scope. These businesses can still choose to join Peppol. A large customer could ask its suppliers for e-invoices before 2029 as part of its own preparation.

"Will HMRC see all our invoices?" Not under the 2029 rules. Invoices pass between businesses’ software providers. HMRC has said it will not receive copies of them in its new role running Peppol in the UK. But HMRC is consulting until 20 January 2027 on whether invoice data could be reported to it in future, and no decision has been made. It makes sense for clients to keep their records clean on the assumption that HMRC may see the data one day.

"Do we need new software?" It depends on what they use now. A client on cloud accounting software should ask their provider whether it will connect to Peppol, either directly or through a partner, and when. Clients on older desktop packages, spreadsheets or paper face the biggest change. Several providers have told the government they will include e-invoicing in their core package at no extra cost, so it is worth asking whether the client’s provider is one of them.

"What will it cost us?" Nobody can give an exact figure yet. The roadmap says free and low-cost e-invoicing products already exist, and that several software providers have committed to including e-invoicing at no extra cost. The UK has not announced any tax relief like Belgium’s.

"When do we need to start?" The legal date is 1 April 2029, and the full rules will be published by April 2028. HMRC says there is no need to set up e-invoicing before those rules are out. But the Belgian experience suggests starting at least six months ahead of the deadline. Clients can start tidying supplier and customer records and reviewing how bills are approved now, because neither depends on the technical rules.

Which clients to talk to first

Not every client needs the same conversation at the same time. A short review of the client list will usually show who needs attention first.

• Clients still invoicing on paper, in spreadsheets or in older desktop software. They will need to change systems, which takes the longest.
• Clients who supply large companies or public bodies. Their customers may ask for e-invoices early, before the legal deadline.
• Clients with unusual invoicing arrangements. Self-billing, frequent credit notes and invoices raised through customer portals all need checking. In Belgium, self-billing turned out to be far more common than expected.
• Clients who approve bills by printing them or forwarding emails. Their process will stop working when invoices arrive as data, as Belgian businesses found.
• Clients joining MTD for Income Tax who are also VAT registered. Choosing software once, with both changes in mind, saves them a second migration.
• Clients that exchange invoices with large customers through EDI. EDI (electronic data interchange) is a direct link between two businesses’ systems. These clients can keep their EDI links after 2029, but they will also need to be able to send and receive e-invoices through Peppol. HMRC guidance is due in autumn 2027.
• Overseas clients registered for UK VAT. The roadmap applies the same rules to them as to UK businesses. Several EU countries treat overseas businesses differently, so these clients may assume they are exempt when they are not.
• Clients who may not be able to use software. Some clients cannot reasonably use software because of their age, a disability or where they live. They may qualify for an exemption, with details of how to apply due by April 2028.

Why accounts payable controls and invoice approval workflows matter more under e-invoicing

Most of the discussion about e-invoicing is about getting invoices in and out. Less attention goes to what happens between a bill arriving and the money leaving the bank. For practices, that gap is where the advisory work is.

In a small business today, a lot of checking happens by accident. Someone opens the PDF, retypes the figures, notices the amount looks high or the supplier name is unfamiliar, and asks a question. E-invoicing removes the retyping. Bills land in the accounting software already filled in, ready to approve. That saves time, but it also removes the moment where a person looked at each invoice. If nothing replaces it, errors, duplicate bills and fraudulent invoices have an easier route to payment.

The fraud figures show why this matters. The Association of Certified Fraud Examiners' 2024 study of 1,921 cases found that billing schemes were among the two most common types of fraud, appearing in 22% of cases. A billing scheme is where someone inside the business submits invoices for goods or services that were never delivered, inflates invoices, or puts personal purchases through as business bills. The median loss was $100,000, and the typical scheme ran for 18 months before anyone found it. The same study found that a lack of internal controls contributed to 32% of frauds, and someone overriding existing controls to 19%.

The controls worth discussing with clients before 2029 are the ones listed in the ICAEW webinar outline:

• Approval workflows. Every bill goes to a named person, or several people, to approve before it can be paid, based on rules such as the amount or the department.
• Budget and purchase-order checks. A bill is compared with what was ordered and what was budgeted before it is approved.
• Segregation of duties. The person who sets up a supplier or enters a bill is not the person who approves it or releases the payment.
• An audit trail. There is a record of who approved each bill and when, so questions can be answered later.

None of these depend on the final UK standards. A client can put them in place now, and they will work the same way whether invoices arrive as PDFs this year or as e-invoices in 2029.

What a practice can do now the roadmap is published

The roadmap has answered some of the questions practices were waiting on. All VAT-registered clients start on the same date, whatever their size. There is no tax relief for software or advice, and penalties will build on the existing rules for VAT invoices. That is enough to start planning, even though the technical detail is still to come. The full timeline is in our guide to the UK e-invoicing mandate.

1. Sort the client list by invoicing method. Note which clients use paper, spreadsheets, desktop software or cloud software, and which are VAT-registered.
2. Ask your software providers about Peppol and pricing. Some providers have committed to including e-invoicing at no extra cost. Find out whether the packages your clients use are among them.
3. Brief your own team. Staff who speak to clients should be able to explain the difference between a PDF and an e-invoice in one or two sentences.
4. Decide how you will charge for e-invoicing work. Where e-invoicing is already in place in Europe, accountants spent much of the rollout helping clients choose software and fix early mistakes. Decide whether that is part of an existing fee or separate advisory work.
5. Write to affected clients. A short note giving the date, whether they are in scope and one next step will be more useful than a long technical briefing.
6. Start the approval controls conversation. Use the e-invoicing news as the reason to review how each client approves bills before paying them.
7. Decide whether to respond to HMRC’s consultation. The consultation on reporting invoice data to HMRC closes on 20 January 2027. Practices see how many different clients keep their records, which is useful evidence for HMRC.
8. Watch for the next stage. HMRC will consult on technical standards and access point certification in spring 2027. HMRC also runs webinars for groups on request through einvoicingengagement@hmrc.gov.uk.

Where ApprovalMax fits for practices and their clients

ApprovalMax does not send or receive e-invoices, and clients will not need it to meet the 2029 rules. That job belongs to their accounting software and its Peppol connection.

ApprovalMax covers the approval controls described above. It works with Xero, QuickBooks Online and NetSuite, and replaces approvals by email or on paper with set workflows. Bills, purchase orders and expenses go to the right approvers according to the client's rules, duties can be separated between different people, and every decision is recorded before payment. It is used by more than 20,000 businesses and accounting firms.

For a practice, that gives a practical answer to the Belgian problem of approvals that relied on printing or forwarding invoices. Setting up a structured approval process for a client now means that when bills start arriving as e-invoices, the checks are already in place and nothing has to be rebuilt in a hurry. See how ApprovalMax works with accounting partners.

UK e-invoicing FAQs for accountants

What is Peppol e-invoicing?

Peppol e-invoicing means sending invoices as structured data through the Peppol network, an international system that lets different accounting software exchange invoices. The UK confirmed Peppol as its core e-invoicing network in June 2026. Belgium has used the same network for mandatory e-invoicing since January 2026.

How does a business get a Peppol ID?

A Peppol ID is the identifier other businesses use to send e-invoices to the right place. In most Peppol countries, a business gets one through its access point provider, often its accounting software, when it switches on e-invoicing. The UK will decide which identifier to use, such as a VAT number or company number, between October 2027 and April 2028.

Do accountants need to become a Peppol access point?

No. Access points are certified providers, usually software companies. Accountants support clients by helping them choose software that connects to Peppol, setting it up correctly and reviewing the processes around it.

Does e-invoicing replace Making Tax Digital?

No. Making Tax Digital covers how businesses keep records and report to HMRC. E-invoicing covers how invoices pass between businesses. Both require digital records, so clients can often meet both with the same software.

Which accounts payable controls should clients have before 2029?

The most useful controls are an invoice approval workflow with named approvers, checks against purchase orders and budgets, segregation of duties between entering, approving and paying bills, and an audit trail of who approved what. These work whether invoices arrive as PDFs or e-invoices.

Is there any government support for the cost of e-invoicing in the UK?

There is no tax relief like Belgium’s 120% deduction on e-invoicing software. HMRC’s roadmap says free and low-cost e-invoicing products already exist, and several software providers have committed to including e-invoicing in their core package at no extra cost.

Watch the ICAEW webinar on preparing clients for e-invoicing

ApprovalMax and Azets ran a webinar with ICAEW on 14 October 2026. Lee Beaumont, UK Head of Outsourcing at Azets, and Rafaella Torres, Corporate Financial Controller at ApprovalMax, covered the questions clients are likely to ask. They also covered the approval controls practices should be discussing with clients now. The session was recorded before the roadmap was published, so please use this post for the latest position. We answered the questions attendees asked in UK e-invoicing questions: Peppol, HMRC and who is in scope.

Watch the webinar on demand

Sources

• GOV.UK: Roadmap for e-invoicing implementation (28 October 2026)
• Grant Thornton: Autumn Budget 2026 tax response
• GOV.UK: One year until MTD for Income Tax launches
• Deloitte: MTD extension to £20,000
• Vandelanotte: Belgian Royal Decree on e-invoicing
• KPMG: Belgium tolerance period
• Peppol Validator: Belgium penalties
• Wolters Kluwer: Lessons learnt from e-invoicing in Europe
• Wallonia economy portal: Belgian tax support measures
• Deductibles.be: 120% deduction for software and advice
• The Invoicing Hub: Belgium recap
• AccountingWEB: Guidance needed to tackle e-invoicing confusion
• Astbury Accountants: What UK businesses should do now
• Bright: What UK accountants must know
• CoStar: ACFE 2024 findings on billing schemes
• ACFE: Occupational Fraud 2024
• ICAEW: webinar event page