Lessons learnt from e-invoicing in Europe: what's next for the UK

• What is the UK's e-invoicing mandate?
• UK e-invoicing timeline and key dates
• What e-invoicing meant for Belgium
• Key learnings from Belgium: start early and examine the whole workflow
• What e-invoicing meant for Italy
• Key learnings from Italy: a fast transition and a shift in accounting work
• How UK accountants can prepare today

It's set to become mandatory for value added tax (VAT) invoices before the end of the decade, and the government expects to share more implementation detail soon.

The strategic advantage for UK accountants, is that you can already learn from European markets that are further along. Belgium made domestic business-to-business (B2B) e-invoicing mandatory from 1 January 2026. Italy has required it for B2B and business-to-consumer (B2C) transactions since 1 January 2019. Both show how businesses and accountants handled software changes, workflows, client support, and preparation for the deadline.

Below, we look at each market and how you can apply its lessons in your own planning.

What is the UK's e-invoicing mandate?

Under the British Government's planned mandate, VAT invoices for B2B and business-to-government (B2G) transactions will need to be issued electronically.

An e-invoice carries structured, machine-readable data that moves digitally between systems. Unstructured files, such as PDFs or scanned invoices, don't meet this definition. 

The UK plans a decentralised approach, with invoices exchanged through each business's chosen software provider. Different platforms will therefore need to work together. The change will affect invoice creation and validation, links with accounting and enterprise resource planning (ERP) systems, and associated workflows and approvals.

UK e-invoicing timeline and key dates

• Budget 2026: The government is expected to publish its implementation roadmap at Budget 2026 on the 28th of October.
• 2029: E-invoicing becomes mandatory for relevant VAT invoices.

Detailed standards and transmission methods are still being developed. Business support is also in development.

For a more comprehensive guide to the rules, read our blog: How should accountants prepare for electronic invoicing in the UK?

What e-invoicing meant for Belgium

Since 1 January 2026, structured e-invoicing in Belgium has been mandatory for in-scope domestic B2B transactions involving businesses established there. B2C is out of scope. The default format is Peppol BIS (Peppol stands for Pan-European Public Procurement Online). Parties can agree an alternative, as long as it complies with the European standard EN 16931.

Belgium also allowed a tolerance period from 1 January to 31 March 2026. During these three months, no sanctions applied for specified difficulties linked to the new obligation. To qualify, businesses had to show reasonable and timely steps to comply. This didn't postpone the mandate.

The concrete deadline was known around two years in advance. Even so, Robin Appeltants, Senior Product Manager SME Software at Wolters Kluwer Belgium, says his team still met some surprises on the ground.

"There are a lot of specific situations at customer sites that you need to take into account that you don't always realise if customers don't tell you about them," he explains.

Self-billing, where the buyer produces the invoice, is one example. Appeltants' team expected a few customers to need it. In the end, hundreds used it.

Key learnings from Belgium: start early and examine the whole workflow

Two lessons stand out from Appeltants' experience of the Belgian rollout:

Businesses underestimated how much processes would change

Many Belgian businesses waited until late 2025, and Appeltants says some expected another delay. Getting used to e-invoicing also took longer than many anticipated.

"It's a different way of working," he says. "A lot of processes change along the way with the use of e-invoicing, and businesses didn't really realise the impact of it on their business."

Take approvals. Some companies printed emailed PDFs and circulated them for checking and sign-off. Once structured invoices arrived through Peppol, there was often nothing to print, which disrupted that process.

Plenty of businesses were juggling a mix of accounting, invoicing, optical character recognition (OCR), and other tools. Some workflow mismatches only surfaced during the rollout.

Starting earlier reduced implementation pressure

Appeltants compares businesses that began six months or a year ahead with those that left it until close to the deadline. The late group faced more stress. Some saw invoices go unpaid, which affected their cashflow.

What e-invoicing meant for Italy

E-invoicing in Italy was introduced in stages. It was already established for public administration before becoming mandatory for B2B and B2C transactions from 1 January 2019.

The practical impact depended on each business's starting point. Many very small businesses needed invoicing software. For larger SMEs with ERP systems, the task was enabling them for e-invoicing.

Accountants became a key source of support, says Gianluca Enea, Associate Director of Technology Product Management, Wolters Kluwer Tax & Accounting, Italy.

"A large section of their customers didn't know what to do or where to start, and they became e-invoicing consultants: what kind of software do you need? How do you use it? How do you fix mistakes? And how do you deal with sales invoices and receiving purchase invoices?"

Key learnings from Italy: a fast transition and a shift in accounting work

Looking back, Enea highlights two things that shaped the Italian rollout.

Preparation helped the transition settle quickly

Enea expected months of technical problems and disruption after January 2019. By February or March, he recalls, the system was broadly working as it does today.

"I think it was very well prepared," he says. In his view, the credit goes to software providers, the authorities, and Italy's earlier public sector e-invoicing.

Accountants' focus moved to review

With invoice data entry automated, Enea says accounting firms shifted their attention towards checking and control. This gave people more time for other work, including client conversations and consultancy.

How UK accountants can prepare today

What happened in Belgium and Italy points to practical steps for UK-based businesses and for the accountants who support them.

For SMEs

1. Start early. Appeltants' advice is to begin at least half a year ahead. That leaves room to learn the system and adapt your processes before the deadline.
2. Review the complete invoicing workflow. Belgian businesses found the changes reached purchase and sales invoice processes, along with approvals for correctness and payment.
3. Check what you already use. In Italy, the starting point shaped the work. The smallest businesses needed new invoicing software, while larger SMEs needed ERP updates.

For accountants

1. Expect clients to need practical guidance. Italian accountants spent much of the rollout helping SMEs choose software and fix early mistakes.
2. Understand how clients currently work. Our UK guide recommends reviewing each client's invoicing processes, software readiness, and integration gaps.
3. Think about the impact on your own practice. In Italy, automation shifted effort into review. That left more room for client conversations and advisory work.

As accountants await further details from the UK government, preparation is key.

Future? Ready.