Customer not on Peppol: how to send a valid invoice

When a Belgian business customer cannot receive structured invoices on Peppol, you do not wait for it to register, and you do not stop invoicing. You issue the invoice on time on paper or as a PDF, and that invoice is legally valid; the customer, not you, is in breach of its duty to receive. Two conditions protect you: the customer must really be unable to receive, and an emailed PDF needs its agreement.

This guide is for anyone who invoices Belgian businesses from OrdoGrid and sees Peppol — ignoré (Peppol skipped) in the send window. If OrdoGrid cannot find a customer, the diagnosis is covered in check whether a customer can receive on Peppol. Who is in scope at all is explained in the Belgian e-invoicing obligation, and why a PDF alone does not count when the customer can receive, in PDF or structured invoice.

What the law says when your customer cannot receive

The fallback rule is art. 53 §2bis, sixth paragraph, of the VAT Code, added by the Law of 10 February 2026 and applied by FPS Finance (the federal tax administration) since 1 January 2026, as announced on 19 December 2025. If the recipient cannot technically receive a structured invoice, itself or through a provider, you need not issue one, but you must still issue an invoice on paper or as an unstructured electronic file such as a PDF. The explanatory memorandum covers both a customer without suitable software and one that cannot be reached on the network.

FPS Finance's B2B FAQ, question 8, adds:

• you choose the transfer method, but an electronic invoice needs the customer's agreement on a secure alternative;
• the invoice sent this way is legally valid and fulfils your invoicing obligation;
• once the customer can receive, you should not send structured invoices retroactively; you may add a clause to the invoice encouraging it to comply.

An infringement counts as a second or later one only if it is established at least three months after the previous infringement that led to a fine; see Belgian e-invoicing penalties.

The fallback does not move your deadline: an invoice must be issued by the 15th of the month after the chargeable event (art. 4 §1 Royal Decree no. 1). “We will be on Peppol next month” is no reason to hold it back.

Fallback invoice

An ordinary invoice on paper or as a PDF, issued because the customer cannot technically receive a structured invoice. It is the one legal invoice for that sale, not a provisional copy.

Step 1: confirm the customer really cannot receive

The fallback rests on a fact you should be able to show later. OrdoGrid checks the client's VAT number on the Peppol network each time you click Envoyer (send). If it finds the customer, Envoi électronique via Peppol is ticked and the fallback does not apply. Otherwise, read the reason.

Before you conclude:

1. In Base Clients (client list), open the client and, in the form Modifier le client (edit client), type the N° de TVA (VAT number) again: after about a second, a box headed Registre belge (BCE) shows the name registered for that number. If it is the customer's official name, the number is right; close the form without clicking Pré-remplir (pre-fill) unless you want to overwrite the client's details. A typo also produces “not registered”, and would put a wrong VAT number on your fallback invoice.
2. On lookup.peppol.org, the tool FPS Finance points to in its Peppol FAQ (question 6), search 0208: followed by the customer's ten-digit enterprise number (its number in the KBO/BCE, the Crossroads Bank for Enterprises). Save a dated screenshot.
3. Ask the customer whether it has a Peppol provider and when reception will be active. A written answer is your best evidence.

When the problem is on your side. If you cannot send, for example because the Autorisation Peppol (Peppol authorisation) is not signed, the fallback does not protect you. You are in breach, and your customer may in principle refuse your invoice; if it accepts the invoice in another form, it keeps its VAT deduction (B2B FAQ, question 7).

Step 2: choose the fallback channel

Step 3: get the customer's agreement in writing

What the rules require. For electronic delivery, the customer's agreement and, according to FPS Finance (B2B FAQ, question 8), a secure method agreed between you. No form or wording is prescribed, and FPS Finance does not define “secure”.

What we recommend. Agree by email, so you can show it later, naming the format (PDF), the address and the period (until the customer can receive on Peppol). In practice, “secure” means an address the customer gave you itself, such as its accounts payable mailbox, a PDF rather than an editable file, and a confirmation of receipt for the first invoice. The French, Dutch and German versions of this article give the template below in those languages.

Subject: Our invoices while you are not yet on Peppol

Dear [name],

On [date] we could not find [legal name], enterprise number [0000.000.000], on the Peppol network. As Belgian VAT law allows (art. 53 §2bis VAT Code), we will send you our invoices as PDF files until you can receive structured invoices on Peppol.

Could you confirm by return email:

1. that you agree to receive our invoices as PDF by email;
2. the address we should use;
3. when you expect to be reachable on Peppol under 0208:[enterprise number].

Invoices sent as PDF will not be sent again on Peppol; from your registration onwards, new invoices will go on Peppol only.

Kind regards, [name, company]

The optional clause on the invoice can be one sentence in its Notes field, for example: “Issued as a PDF because your company could not receive structured invoices on Peppol on [date]. Please register to receive on Peppol.” FPS Finance prescribes no wording.

Step 4: send the fallback invoice from OrdoGrid

OrdoGrid has no automatic email fallback: you choose the channel.

1. Open the invoice and, if you use the clause, add it in Notes, which is printed on the PDF.
2. Click Envoyer. The window Envoyer la facture (send the invoice) shows Peppol — ignoré with the reason.
3. Check that Email is ticked and that the address is the one the customer confirmed; correct it in the field if needed. Without a saved client email the window shows Aucun email configuré (no email configured): type the address.
4. Click Sauvegarder & Envoyer (Save & Send). OrdoGrid saves, emails the invoice with its PDF attached and shows the result per channel. The status moves from Brouillon (draft) to Envoyée (sent).
5. Alternative to steps 2–4, if you want your own subject or message: in the invoice list, use the action Send by email (in the invoice drawer the same action is labelled Envoyer): fill Email subject and Personal message (optional), keep Attach the document PDF ticked and click Send email.
6. Alternative for paper, instead of steps 2–4: click PDF, print and post the invoice, then set the status to Envoyée with the Statut action.
7. In Base Clients, note in the client's Notes the date and result of the check, the agreed channel and the address.

The email comes from contact@ordogrid.com under your company name, with replies to your company address; warn the customer so its spam filter does not block it. It never contains UBL XML and has no read receipt, so ask for a confirmation. The history appears under Envoi et Paiement (sending and payment) in the invoice sidebar.

Step 5: when the customer joins Peppol

1. Confirm. Search the customer on lookup.peppol.org, or click Envoyer on the next invoice: Envoi électronique via Peppol is then ticked automatically.
2. Send new invoices on Peppol only. Untick Email in the send window. In September 2026 the Belgian Peppol service providers' forum recommended sending exclusively via Peppol when the recipient can receive there; a recommendation, not a rule. Peppol itself cannot detect duplicates (specific FAQ, question 4).
3. Leave fallback invoices alone. The globe button Envoyer à Peppol (send to Peppol) in the invoice list stays available for them, because they never went on Peppol; using it would deliver the same invoice twice. The guard Déjà envoyé sur Peppol (already sent on Peppol) on the globe button, shown as Déjà envoyé via Peppol in the send window, only blocks a second Peppol send.
4. Corrections. The rule that a credit note follows the format of the original invoice (art. 53 §2bis VAT Code) applies only when the original is a structured invoice (specific FAQ, questions 5 and 23). For a PDF original there is no format requirement, and a PDF credit note remains possible if the customer accepts it. Agree the channel for such a credit note with the customer and your accountant. In OrdoGrid a credit note starts from the invoice with Note de crédit (credit note) and is sent like an invoice.

Worked example: a customer joining Peppol late

Graphisme Renard SRL, a design studio in Namur, redesigned the website of Ferronnerie Dumont SRL, a metalworks company in Liège. Both are VAT-registered and established in Belgium. The site went live on 30 September 2026, so the invoice must be issued by 15 October 2026.

1. Monday 12 October. Envoyer shows Peppol — ignoré with Le client n'est pas enregistré sur le réseau Peppol. Renard retypes the number in the client form: the Registre belge (BCE) box shows Ferronnerie Dumont SRL, so the number is right. lookup.peppol.org finds nothing for 0208:0987654394, 9925:BE0987654394 or the name; Renard saves the screenshots.
2. Same day. By phone, Dumont's manager says the company has just signed with a Peppol provider and expects to receive on Peppol from early November. Renard sends the agreement request from Step 3.
3. Wednesday 14 October. Dumont confirms by email: PDFs to its accounts mailbox.
4. Thursday 15 October. Renard dates F-2026-0118 that day, adds the clause in Notes, leaves only Email ticked with the confirmed address and clicks Sauvegarder & Envoyer. The client's Notes read: “12 Oct 2026: not on Peppol (0208, 9925, name). 14 Oct: PDF by email agreed. F-2026-0118 emailed 15 Oct.”
5. Tuesday 3 November. Dumont announces its registration; lookup.peppol.org lists 0208:0987654394 with Peppol BIS invoices and credit notes.
6. Thursday 5 November. F-2026-0131 for October hosting and maintenance: €250.00 + €52.50 VAT (21%) = €302.50. Envoi électronique via Peppol is ticked; Renard unticks Email and sends. In Peppol → Outbox the row goes from En file (queued) to Traité (delivered on the network; this does not mean the customer has accepted it).
7. Friday 13 November. Dumont pays €4,840.00; Renard records it with Record payment in the Settlement panel and the invoice shows Payée (paid). F-2026-0118 was never sent again.

Waiting for the registration would have made F-2026-0118 late; clicking Envoyer à Peppol on it on 3 November would have delivered the same €4,840.00 invoice twice.

Customers outside this procedure

Common mistakes

Evidence to keep

What the law requires. Keep invoices for seven years from 1 January of the year after issue (art. 60 §3 VAT Code, as amended by the Law of 18 December 2025, which brought the period back from ten to seven years). No legal text prescribes how to document a lookup.

What we recommend. Be able to show why each fallback invoice did not go on Peppol.

What OrdoGrid does. It keeps your documents but gives no archiving guarantee: export your own copies regularly, for example by selecting rows in the invoice list and clicking Download (tooltip: Download as ZIP).

FAQ

Is an invoice sent by email valid in 2026 if my customer is not on Peppol?

Yes, if the customer cannot technically receive structured invoices. FPS Finance says the invoice sent by other means is legally valid and fulfils your invoicing obligation. Emailing it needs the customer's agreement on a secure alternative; a paper invoice does not.

Can I be fined for sending a PDF because my customer is not on Peppol?

Not for using the fallback. The customer risks €1,500, then €3,000, then €5,000 for lacking the means to receive. You remain exposed to the ordinary fines if the invoice is late or incomplete, or if the customer could in fact receive, for instance when the miss came from a wrong number.

Should I resend the invoice on Peppol once my customer registers?

No. FPS Finance says suppliers should not send structured invoices retroactively. Send only new invoices on Peppol and do not use Envoyer à Peppol on the earlier ones.

My customer is on Peppol but asks for a PDF. Can I email it instead?

No. Between businesses established in Belgium, the structured invoice is the only legal invoice when the customer can receive. Send it on Peppol; a PDF copy is optional and does not replace it.

How long can I keep sending PDF invoices to the same customer?

As long as it cannot technically receive. The law sets no end date, but check again before every invoice; OrdoGrid does so each time you click Envoyer. The customer, meanwhile, stays exposed to fines.

Does OrdoGrid switch to email automatically when the client is not on Peppol?

No. The send window shows Peppol — ignoré with the reason, and you decide: tick Email, or download the PDF for paper.

Can I register my customer on Peppol myself?

No. Only the customer can register, through a Peppol provider of its choice. Until then, issue fallback invoices.