Since January 1, 2026, any invoice issued between Belgian VAT taxpayers must be a <strong>structured</strong> electronic invoice in Peppol BIS format. PDF sent by email is no longer sufficient. Here's what the reform concretely imposes.

E-invoice ≠ PDF by email

This is the first misunderstanding to clear. A PDF invoice is not an electronic invoice in the sense of the reform: it's simply a paper invoice scanned or generated as PDF. It remains intended for the human eye.

A structured e-invoice is an XML file following a precise European standard (EN 16931), readable and automatically integrable by the recipient's accounting software. It's this format that becomes mandatory.

The Peppol network is the transmission channel: invoices transit through a certified access point (an "Access Point") rather than by email. It's the equivalent of an interbank network for invoices.

Who is concerned?

Any B2B operation between two Belgian VAT taxpayers. The rule does not concern invoices to consumers (B2C), nor invoices to foreign countries — for now. An international extension is planned in the medium term.

There is no threshold: whether you issue 10 invoices per year or 10,000, the obligation applies from the first 2026 invoice.

What must be put in place

Three technical elements:

Peppol-compatible invoicing software. Most Belgian solutions (Odoo, Billit, Yuki, Silverfin, Exact, Horus…) are compliant or will be by end of first quarter. Non-compatible software = migration obligation.

Connection to the Peppol network. Concretely, this goes through a third-party Access Point — often offered by your accounting software as an add-on. Average cost: between €5 and €20/month depending on volume.

Verification of your clients' registration. Your clients must themselves be registered on the Peppol network to receive your invoices. Most will be quickly — but anticipating avoids blockages.

Penalties

An invoice issued outside the Peppol format after January 1, 2026 is non-compliant. This means: no VAT deduction for the client, correction obligation, and eventually administrative fines. The SPF Finances announced an operational tolerance period until June 30, 2026, but the legal obligation itself is in force.

The hidden benefit

Beyond the constraint, Peppol invoicing brings three concrete benefits once installed. Zero entry errors on the client side — the invoice enters directly into their software. An average payment delay reduced by several days (fewer bounces, fewer disputes). A considerably simplified tax verification trail.

In other words, the regulatory constraint largely finances its own cost, provided you use the new format as an opportunity to streamline the invoice-payment-accounting cycle. For SMEs still in Word or spreadsheet invoicing mode, this is the time to skip a whole generation of tooling.