Peppol e-invoicing in Belgium: the real problems businesses face in 2026

Peppol e-invoicing is here: and with it, the first real problems

Since January 1st 2026, electronic invoicing via Peppol has been mandatory between VAT-registered businesses in Belgium. Most businesses are equipped, invoices are flowing, and the system works. But after the first months of use, real field problems are emerging.

Not theoretical problems. Concrete issues that accountants, managers and self-employed professionals face every day. Here are the three main ones, and how to solve them.

XML without PDF: the number 1 headache

The Peppol network transmits invoices in structured XML format (UBL). It's a format designed for machines, not humans. The problem? Attaching a PDF is optional in the Peppol standard. And many suppliers don't include one.

In practice, you receive an invoice that looks like this:

Not exactly the document you'd visually check, forward to your accountant, or archive.

Even worse: attachments... but not the invoice

There's an even more confusing scenario: some suppliers do attach files to their Peppol invoice, but they're not PDF copies of the invoice. They're general terms and conditions, delivery notes, certificates... everything except the actual invoice in a readable format.

Result: you have attachments, you think you have the PDF, but when you open it, it's not your invoice.

Why this is a real daily problem

• Your accountant needs a visual document to verify and encode
• Archiving a raw XML file isn't practical
• Checking an invoice before payment requires being able to read it
• Online converters are unreliable and time-consuming

The solution: Peppol Box automatically generates a PDF

Peppol Box solves this problem seamlessly:

• If your supplier attached a PDF → Peppol Box displays the original PDF
• If the invoice arrives as XML only → Peppol Box automatically generates a professional PDF from the structured data

Either way, you always have a readable PDF, available immediately. No action required on your part.

9925, 0208, 0280: the Peppol identifier confusion

This is the second major problem, and it's far less visible than the first. Many businesses don't realise they have an identifier issue... until an invoice doesn't reach them.

The mandatory identifier: 0208

In Belgium, the primary Peppol identifier is 0208, which corresponds to your CBE enterprise number (e.g. 0208:0123456789). This is the one your suppliers and clients should use to send you invoices.

The 9925 trap

9925 is a legacy identifier based on the VAT number (e.g. 9925:BE0123456789). Many businesses historically registered on 9925, and some software still uses it by default.

The problem: if your supplier sends to 0208 but you're only registered on 9925 (or vice versa), the invoice won't reach you. Or worse, you receive duplicates if you're registered on both without knowing it.

What about GLN (0088)?

Some large companies also use the GLN (Global Location Number) with prefix 0088. It's an optional identifier, mainly used in retail and distribution. It doesn't replace 0208.

What to do?

• Check that your business is registered on 0208 (CBE enterprise number)
• If you're also on 9925, make sure both point to the same access point
• Communicate your 0208 identifier to your business partners as the primary one
• Use the Peppol search tool in Peppol Box to check how your clients and suppliers are registered

The April 1st 2026 deadline: what it really means

Many businesses have heard about a "postponement to April 1st 2026" for e-invoicing. But this deadline is often misunderstood.

What the deadline does NOT mean

It is not a general postponement for all businesses. The obligation to receive and issue electronic invoices via Peppol has been in force since January 1st 2026. That's non-negotiable.

What the deadline actually means

The grace period until April 1st 2026 is a tolerance period mainly for businesses that:

• Have started migration projects with software vendors whose Peppol implementation isn't finished yet
• Use complex ERPs requiring custom integrations
• Have specific invoicing processes that need significant technical development

Small businesses are NOT affected by this deadline

If you're an SME, a freelancer or a retailer, there's no reason to wait until April 1st. Affordable, simple solutions exist:

• Peppol Box: operational in minutes, no technical integration needed
• Flexina: full invoicing software with Peppol compatibility
• Other Peppol-compatible invoicing software available on the Belgian market

The April 1st deadline is for businesses with a genuine technical issue involving a vendor that isn't ready. Not for those who simply haven't started yet.

The Peppol directory: it doesn't tell the whole story

When checking whether a client or supplier is on Peppol, the first instinct is to search the official Peppol Directory: directory.peppol.eu. But this directory is misleading.

What the Peppol Directory really is

The Peppol Directory is a voluntary public listing. It works like a phone book: only businesses whose Access Point has chosen to publish their information appear in it. In practice, roughly 90 to 95% of Peppol participants are listed.

This means that 5 to 10% of active Peppol participants don't appear in the Directory. If you can't find a company there, it does not mean they're not on Peppol.

The tool to use: Peppol Practical (Helger)

For a reliable check, use peppol.helger.com. This tool performs a direct query against the Peppol technical infrastructure (SMP/DNS lookup), exactly as an Access Point would when sending an invoice.

The difference is fundamental:

Criteria	Peppol Directory (directory.peppol.eu)	Helger (peppol.helger.com)
Source	Voluntary centralised listing	Direct query on the Peppol network
Coverage	~90-95% (voluntary opt-in)	100% of actual participants
Reliability	May contain stale data	Real-time, always up to date
Search	By name, country, partial ID	By exact identifier (0208:xxx)
False negatives	Yes: absence ≠ not on Peppol	No: if the lookup fails, the company is genuinely not registered

In short: use the Peppol Directory to discover companies by name. Use Helger to verify that a specific Peppol identifier is actually active on the network. Never rely on the Directory alone to conclude that a company is not on Peppol.

Foreign suppliers and consumers: Peppol's grey areas

Belgium's mandatory Peppol e-invoicing creates confusion in two common scenarios: cross-border transactions and invoices to consumers.

Foreign suppliers are not obligated

The Belgian obligation covers B2B transactions between VAT-registered businesses in Belgium. A supplier based in France, Germany or the Netherlands is not legally required to send you an invoice via Peppol, even when invoicing a Belgian company.

In practice:

• You cannot require your foreign suppliers to use Peppol
• Many foreign suppliers voluntarily adopt Peppol to simplify exchanges with their Belgian clients
• An EU-wide cross-border e-invoicing obligation is expected from 2030 (ViDA directive)
• In the meantime, invoices from foreign suppliers will often continue arriving by email or post

Consumers (B2C): not covered by Peppol

If you invoice consumers (non-VAT-liable customers), you are not required to use Peppol for those invoices. Paper invoices and PDF by email remain perfectly legal for B2C.

A private individual cannot register on the Peppol network: there is no Peppol identification mechanism for non-VAT-liable natural persons.

Warning: even B2C businesses must receive via Peppol

This is a crucial point many B2C businesses overlook. Even if you only invoice consumers (hairdresser, restaurant, retail shop...), you must still be able to receive Peppol invoices from your suppliers. Your suppliers are B2B businesses that are required to invoice you via Peppol.

Every VAT-registered business in Belgium must have an active Peppol receiving endpoint, regardless of their customer base. Penalties for non-compliance: EUR 1,500 for a first offence, EUR 3,000 for a repeat offence within 3 months.

Accounting software that seized the opportunity: the "all-in-one" trap

This may be the most frustrating problem of the Peppol transition in Belgium. Many accountants were approached by their accounting software vendors with an enticing promise: "activate our invoicing module, and all your clients' Peppol invoices will be automatically imported into your software."

What actually happened

Accounting software vendors saw the Peppol obligation as a commercial opportunity to push their own invoicing solution on their users. Their argument: "only our software can automatically retrieve Peppol data." This is false. Any Peppol-compatible software can receive and process UBL invoices.

The reality on the ground:

• Clients signed up on unusable invoicing platforms, complex and unsuitable for their needs
• Businesses that aren't receiving their invoices because the accounting software's Peppol module simply isn't working properly
• No support available: accounting software vendors aren't Peppol specialists and don't have the teams to handle network-level technical issues
• Accountants forced into the role of helpdesk for their clients, wasting precious time on technical problems that aren't theirs to solve

Stick to what you know best

Accounting software is built for accounting. Electronic invoicing via Peppol is a profession in its own right, requiring network expertise, responsive technical support, and a platform designed for managing Peppol documents.

That's exactly what Flexina and Peppol Box do: solutions built specifically for Peppol, with:

• A simple, reliable platform that works from minute one
• Local, responsive customer support when problems arise, not a ticket in an endless queue
• Peppol expertise: it's our core business, not a last-minute module bolted onto accounting software
• Accounting export to any accounting software, with no vendor lock-in

If your accountant pointed you towards their accounting software's invoicing module and it's not working well, that's not Peppol's fault. It's an unsuitable solution. Reliable alternatives exist.

How to avoid these problems?

Here's a practical checklist to be compliant with Peppol e-invoicing in Belgium:

• Check your Peppol registration: are you registered on 0208 (CBE enterprise number)?
• Test reception: ask a partner to send you a test invoice via Peppol
• Check your PDFs: when you receive an invoice, do you get a readable PDF or just XML?
• Share your identifier: inform your partners of your 0208 Peppol number
• Check your suppliers: use the Peppol search to see which identifier they're registered on

Peppol Box helps you manage all of this simply: automatic reception, guaranteed PDF, built-in Peppol search tool, and support for identifier issues.

Peppol e-invoicing works. But it requires a minimum of vigilance on these three points. Get properly equipped, and these problems will no longer be problems.