E-invoicing with Peppol: Belgium’s B2B obligation and the road to 2030

01Where Belgium stands in autumn 2026

The law of 6 February 2024, which amended the VAT Code and the Income Tax Code 1992, made structured electronic invoicing mandatory for domestic transactions between businesses from 1 January 2026. Royal decrees set out the technical rules and the penalties. The federal government’s e-invoicing site (opens external site), run by FPS BOSA with FPS Finance, publishes the practical guidance.

FPS Finance did not postpone the obligation, but it announced a tolerance for the first three months of 2026: no penalties for infringements of the new rules, provided the business could show it had taken reasonable and timely steps to comply. That period ended on 31 March 2026. Since then, the administration can impose fixed penalties: EUR 1,500 for not having the technical means to issue and receive e-invoices, EUR 3,000 for a second infringement and EUR 5,000 for each further one.

02What counts as an e-invoice

An e-invoice in the sense of the obligation is a structured invoice: a file that software can read without human interpretation, built on the semantic data model of the European standard EN 16931. A PDF, a scanned paper invoice or a Word document is not an e-invoice, even when it arrives by email. A structured invoice may still carry a PDF as an attachment for people to read; the structured data is what counts.

In Belgium, the default is the Peppol network, with invoices in the Peppol BIS Billing 3.0 format, the Peppol specification of EN 16931 in the UBL syntax. Parties may agree on another network or format, as long as the invoice still follows EN 16931. In practice, Peppol is what your customers and suppliers will expect.

03How the Peppol network works

Peppol is an international network and a set of specifications for exchanging business documents, governed by OpenPeppol, a non-profit association based in Brussels. It follows a four-corner model. Your ERP (corner one) hands the invoice to your access point (corner two), which delivers it to the access point of your customer (corner three), which passes it to your customer’s system (corner four). Before sending, the access point checks the network’s address book, the Service Metadata Locator, which points to a Service Metadata Publisher, to see whether the receiver is registered and which documents it can receive.

The consequence is simple and powerful: you sign one contract with one access point provider and reach every participant on the network, whichever provider they use. In Belgium, a company is usually identified on Peppol by its enterprise number. Many ERP and accounting packages include an access point service, and specialised providers offer one for larger volumes and other document types such as orders and credit notes.

• Registration: your company is registered on the network with its identifier and the document types it can receive. A missing or wrong registration is a frequent reason why invoices do not arrive.
• Validation: access points check invoices against the Peppol BIS Billing 3.0 rules. An invoice that fails is rejected before it reaches the customer.
• Delivery status: the network confirms technical delivery. Business responses, such as accepted, disputed or paid, are separate messages and depend on what both parties support.

04Who is in scope, and what changes next

The obligation applies to VAT-registered businesses established in Belgium, for invoices between them on transactions located in Belgium. Cross-border invoices fall outside the Belgian obligation for now. Exclusions include businesses that only make supplies exempt under Article 44 of the VAT Code, businesses in bankruptcy, and foreign businesses without a fixed establishment in Belgium. The federal e-invoicing site offers an online tool to check your own situation. Invoices to Belgian public bodies run through Mercurius, the government’s e-invoicing platform, which is connected to Peppol.

The next step is e-reporting: the federal government plans that, from 1 January 2028, invoice data will also be reported to the tax administration. The legislation for that step was not final when we wrote this article. A set-up that already runs all invoicing through Peppol, with clean data, is the best starting point for it.

05The wider EU picture

Two EU texts frame the national rules. Directive 2014/55/EU (opens external site) requires public contracting authorities to accept electronic invoices that follow EN 16931, which is why invoicing to government went electronic first in most countries. The VAT in the Digital Age package (ViDA), with Council Directive (EU) 2025/516 (opens external site), was adopted on 11 March 2025 and entered into force on 14 April 2025. Since then, Member States may require domestic e-invoicing without first asking the EU for a derogation. From 1 July 2030, e-invoicing and digital reporting become mandatory for intra-EU B2B supplies, and by 1 January 2035 national real-time reporting systems have to align with the EU model.

Until then, each country moves at its own pace and with its own architecture. Some use Peppol, some a national platform that clears every invoice, some a mix. For a group that invoices in several countries, that means one integration design with several outlets.

06Connecting your ERP: where projects succeed or stall

Sending a first invoice over Peppol can take an afternoon. Running all invoicing over it without manual work takes design. The effort sits in master data, validation, inbound processing and archiving, not in the network.

• Master data first. Every customer needs a correct identifier, VAT number and address, and every item a unit of measure and VAT category that map to the codes the standard expects. Check customers’ registration on the network before the first send, and keep the check running, because companies change providers.
• Validate before you send. Run the same business rules the access point applies inside your own process, so that a rejected invoice is caught and corrected in the ERP, not discovered weeks later by a customer who never received it.
• Design the inbound flow. Structured invoices can be matched automatically to the supplier, the purchase order and the goods receipt, and routed for approval only when something does not match. That is where most of the efficiency gain is. Invoices that still arrive on paper or as PDF, for example from suppliers abroad, can go through document capture into the same flow.
• Keep the original. The structured file you sent or received is the invoice. Archive it unchanged, with the delivery evidence, for the statutory retention period, and make sure people can still find and read it during an audit.
• Monitor the flow. Failed deliveries, rejections and invoices waiting for approval belong on a dashboard with an owner, not in a mailbox.

In Odoo, the Belgian localisation supports sending and receiving over Peppol, so the work is mostly configuration, master data and approval flows. In SAP landscapes, the choice is usually between SAP’s own compliance tooling for electronic documents and an integration with an external access point; both need the same attention to master data and error handling. Where several ERPs, a webshop and a group core all invoice, a shared integration layer keeps formats, validation and monitoring in one place instead of in every system.

07A practical plan

1. 01Inventory every invoicing flow. Which systems issue and receive invoices and credit notes, in which countries, and through which channels, including webshops, subscription billing and intercompany flows.
2. 02Choose the access point model. The one built into your ERP, a specialised provider, or a shared integration layer for several systems. Decide on volumes, document types beyond invoices and the countries you need.
3. 03Clean master data. Identifiers, VAT numbers, units and VAT categories for customers, suppliers and items.
4. 04Test with real partners. Exchange invoices with your largest customers and suppliers before you switch, and check how their systems process yours.
5. 05Automate inbound processing. Matching, approval and booking, with exceptions routed to people.
6. 06Archive and monitor. Keep the structured originals and delivery evidence, and give failed messages an owner.
7. 07Plan for reporting. Design data flows now so that invoice data can also go to the tax administration when e-reporting arrives, in Belgium and in other countries where you trade.

08What to watch

• The Belgian e-reporting legislation and its technical specifications, planned for 1 January 2028.
• National implementation of ViDA, including which countries extend the 2030 obligation to domestic transactions.
• The roll-out in France and Spain, and the end of the German transition periods in 2027 and 2028.
• New releases of Peppol BIS Billing 3.0 and of the validation rules your access point applies.

E-invoicing rules are moving in almost every country we work in. Date every internal note you write on them, and check the official sources before each design decision.