What is Peppol? How the e-invoicing network works in Belgium

Peppol is an open network with shared rules through which certified service providers exchange structured business documents, such as invoices and credit notes, for their customers. It is not a file format, not a portal you log in to and not a PDF sent by email. You join through a provider, usually called an access point, and others reach you at your participant ID: in Belgium, 0208 followed by your enterprise number.

Since 1 January 2026, an invoice in Peppol BIS format sent over Peppol is the legal default between businesses established in Belgium. This reference explains how the network works, what the law asks and where each concept appears in OrdoGrid. Who exactly is covered is in the Belgian e-invoicing obligation; the setup screens are covered in Set up Peppol in OrdoGrid.

Four things people mean by "Peppol"

"We are on Peppol" can refer to four separate layers. Most misunderstandings come from mixing them.

Access point

A certified Peppol service provider. In Belgium it must join OpenPeppol, sign an agreement with the Belgian Peppol Authority, pass conformance tests and hold Peppol certificates. As a business you normally deal only with your software or provider.

Peppol is neither Belgian nor limited to invoices: schemes exist for many countries' identifiers (9930 for German, 9944 for Dutch VAT numbers) and the network also carries orders and despatch advices (Peppol BIS 3).

How one invoice travels: the four-corner model

1. Create. The supplier's software produces Peppol BIS XML carrying both parties' participant IDs.
2. Locate. C2 queries the SML (Service Metadata Locator) by DNS to learn which SMP holds the customer's ID. Each ID is registered with one and only one SMP (SML 1.3.0, §2.1).
3. Check capability. The SMP (Service Metadata Publisher) says whether the customer accepts this document type (invoices and credit notes are separate types) and gives C3's address and certificate.
4. Transmit. C2 sends over AS4, the only Peppol transport since 2023, secured with certificates issued by OpenPeppol. C3 returns a technical receipt.
5. Deliver. C3 passes the invoice to the customer's software, which can send business responses back the same way.

OpenPeppol's Network Policy describes three layers: protocol (discovery, transport, certificates), messaging (creating and validating documents) and business (C1 to C4). Delivery is a network question; correct lines and VAT are a document question.

Peppol does not promise real-time delivery. FPS Finance says most invoices arrive within minutes to a couple of hours; contact your software supplier if a delay exceeds one working day (Peppol FAQ, question 9).

Finding a participant: SML, SMP, Directory and lookup

Sending needs no registration; only receiving is published. That is why one provider can send for you while another receives.

Beyond the invoice: corrections, responses and status messages

A receipt says the network delivered, an Invoice Response says what the customer decided, and only your bank statement shows payment. Peppol does not detect duplicates either; that is your software's and your accountant's job (FPS Finance specific questions, question 4).

Belgian Peppol IDs: the enterprise number comes first

• 0208 is compulsory. Every Belgian participant is registered under 0208 and its enterprise number; providers are contractually bound to do this (Belgian Peppol Authority requirements; FPS Finance Peppol FAQ, question 4).
• Extras are optional. The VAT number (scheme 9925) or a GLN may be added, never instead of 0208. Scheme 9956 was removed in 2023 and 0193 is deprecated.
• Do not ask customers for a Peppol ID. Deliver to their enterprise number (B2B FAQ, question 15).

An enterprise number has ten digits, starts with 0 or 1 and ends in a mod-97 check: 97 minus the remainder of the first eight digits divided by 97. For 01234567, the remainder is 48, so the check is 49 and the number is 0123.456.749. Peppol validation rejects an invoice whose 0208 IDs fail this check (rule PEPPOL-COMMON-R043). More in Peppol ID explained.

What Belgian law requires since 2026

The law, our recommendations and the product are three different things. This table states the law and official FPS Finance positions as of October 2026.

What we recommend, not the law: check each business customer on lookup.peppol.org before its first invoice, put any agreement on another format in writing (as FPS Finance advises), and send each invoice once, on Peppol only, to customers who receive there. Belgian Peppol providers adopted that last point as a recommendation on 8 September 2026. Ask your accountant about special cases.

Peppol, PDF, EDI and Mercurius

In OrdoGrid: where each concept appears

OrdoGrid connects to Peppol through a certified access point, which acts as C2 when you send and C3 when you receive. Peppol screens are in French in every interface language.

What OrdoGrid does not do:

• offer Peppol to companies without a BE VAT number;
• reach clients without a VAT number on Peppol (email them instead);
• switch to email automatically;
• offer a Peppol test mode (every send is real);
• take over an inbox with a migration key (your old provider must deregister you first);
• provide a Mercurius-specific feature.

From zero to a first Peppol invoice

1. In Profil entreprise (company profile, editable by owners and administrators), enter your BE VAT number in Numéro de TVA (Optionnel).
2. Open Peppol, enter or confirm your full name in Nom complet du signataire (signatory's full name), tick the confirmation and click Signer et confirmer l'autorisation (sign and confirm the authorisation).
3. On Réception Peppol, click Activer la réception, or Continuer en envoi seul if another provider receives for you.
4. Create the invoice with Nouvelle facture (new invoice), click Envoyer, keep Envoi électronique via Peppol ticked, untick Email (ticked automatically when the client has an email address; the PDF is already embedded in the Peppol invoice) and click Sauvegarder & Envoyer (save and send).
5. In Peppol → Outbox, wait for Traité.

Worked example: one invoice across the four corners

Atelier Nord SRL, a joinery workshop in Namur (enterprise number 0123.456.749, Peppol ID 0208:0123456749), receives through OrdoGrid. Its customer Studio Berg BV, a design office in Ghent (enterprise number 0456.789.034), receives on Peppol through its accounting software. On 5 October 2026 Atelier Nord issues invoice F-2026-0187, due 4 November, quoting Studio Berg's order PO-2026-311:

1. C1. On Envoyer, OrdoGrid finds 0208:0456789034 from Studio Berg's VAT number and ticks Envoi électronique via Peppol; Atelier Nord unticks Email, so the invoice goes out once. Studio Berg's client record has Exiger un bon de commande pour les factures (require a purchase order for invoices) ticked, so the editor shows N° bon de commande. PO-2026-311, entered there, becomes the buyer reference. Peppol BIS requires a buyer or order reference; without a PO, OrdoGrid uses the communication or the invoice number.
2. C2. OrdoGrid validates the invoice, embeds the PDF and hands it to its access point, which queries the SML, reaches Studio Berg's SMP and confirms it accepts invoices.
3. C3 and C4. The invoice travels over AS4 to Studio Berg's access point; the Outbox moves from En file to Traité within minutes, and Studio Berg's software imports €2,390.00 net, €501.90 VAT, €2,891.90 total.
4. Response. On 7 October Studio Berg answers UQ (under query) with reason QTY: only 5 hours were worked. The response appears on F-2026-0187's row in Peppol → Outbox.
5. Correction. On 8 October Atelier Nord selects the invoice in Factures and clicks Note de crédit: credit note NC-2026-0019 for 1 hour, €65.00 + €13.65 VAT = €78.65, sent on Peppol with a reference to F-2026-0187, as a correction to a structured invoice must be.
6. Result. Studio Berg answers AP (approved) on 9 October. The Settlement panel shows Credits €78.65 and Outstanding €2,813.25 (€2,891.90 − €78.65). Payment is recorded with Record payment when the money arrives.

The same week:

Common mistakes

Evidence to keep

Keep invoices for seven years from 1 January of the year after issue (art. 60 VAT Code, as restored by the Law of 18 December 2025), longer in some immovable-property cases. We recommend keeping:

• the XML of every invoice and credit note sent and received (FPS Finance strongly recommends keeping the original format);
• delivery status, dates and Invoice Responses;
• for each fallback invoice, the date, lookup result and Peppol — ignoré reason;
• written agreements on another format or channel;
• your authorisation (Peppol → Statut → Autorisations) and reception start date ("Depuis le").

In OrdoGrid, select rows in the Peppol list and download a ZIP with xml/ and pdf/ folders. OrdoGrid keeps the exact XML, PDF and hashes of each transmission but is not a legal archive and states no retention period, so keep your own copy. See invoice archiving in Belgium.

FAQ

What is Peppol in simple terms?

An open network through which certified providers exchange structured documents such as invoices for their customers. You join through a provider and are reached at your participant ID, in Belgium 0208 plus your enterprise number.

Is Peppol mandatory in Belgium?

Since 1 January 2026, businesses established in Belgium must exchange structured invoices, and Peppol BIS over Peppol is the legal default. Another EN 16931 channel needs an agreement, and you must still be able to send and receive on Peppol. Consumer and cross-border invoices are out of scope.

Is a PDF invoice still valid?

Not for in-scope business invoices: the structured invoice is the legal one and a PDF is an optional copy. A PDF remains the invoice when the customer cannot receive on Peppol, for consumers and for cross-border sales.

How do I check whether a customer is on Peppol?

Enter 0208, a colon and its enterprise number on lookup.peppol.org and look for the invoice and credit-note types. It shows receiving, not sending. OrdoGrid also checks when you click Envoyer.

How long does a Peppol delivery take?

Usually minutes to a couple of hours, according to FPS Finance; real-time delivery is not guaranteed. After one working day, contact your software supplier. In OrdoGrid, delivery shows as Traité.

Can I send through one provider and receive through another?

Yes. Sending needs no registration, but only one provider receives for your Peppol ID, and your customers' Invoice Responses go to it. In OrdoGrid, choose Continuer en envoi seul in that case.

What is the difference between Peppol and Mercurius?

Peppol is the network; Mercurius is the public sector's mailroom that receives over it. You send through your access point to the authority's Peppol ID, or type the invoice into the Mercurius portal if you have no Peppol software.

Does Peppol send my invoice data to the tax administration?

Not today. E-reporting is planned for 2028; a preliminary draft law was approved on 18 July 2026 but is not law yet. See e-reporting 2028.