May I email a PDF if my customer isn’t on Peppol?

Yes, if your customer agrees and you agree on a secure channel. Without that agreement, use another way, such as paper.

Do I have to resend that invoice via Peppol later?

No. Once your customer’s system works, send new invoices via Peppol. Earlier invoices don’t need to be resent.

My software can’t find my customer, but they say they’re on Peppol. Who is right?

Often both: they are registered under the other ID. Check 0208 and 9925 and use the one that receives invoices.

Am I at fault if my customer can’t receive?

According to the official FAQ, the invoice you issue another way fulfils your invoicing obligation. The penalty risk lies with the customer.

Customer not on Peppol? How to send your invoice

Check both Belgian Peppol IDs first

A “receiver not found” message often means your software only tried one ID. A Belgian company can be on Peppol under 0208 (enterprise number, e.g. 0208:0403170701), under 9925 (VAT number, e.g. 9925:BE0403170701), or under both. If your customer is only registered under 9925 and your software looks up 0208, they seem absent while they can in fact receive.

Enter the number in the check. For each ID you see whether it is registered and accepts invoices:

Receives invoices under 0208 or 9925: put that ID in the customer record and send again.
On Peppol, but no invoices: your customer is registered without the invoice document type. Ask them to have their Peppol provider add it.
Registered under neither: your customer can’t (yet) receive via Peppol. Read on.

Your customer isn’t on Peppol at all: what may you do?

The federal government answers this in its e-invoicing FAQ: if your customer isn’t ready to receive via Peppol, you as the sender may choose another way to transmit the invoice. If you send it electronically, for example a PDF by email, your customer has to agree and you agree on a secure alternative.

An invoice sent that way is legally valid: it fulfils your own invoicing obligation. The risk of a penalty lies with the customer who can’t receive.

Use paper, or a PDF through a channel your customer has agreed to.
You may add a sentence to the invoice asking your customer to get compliant. That is optional.
Note when you checked both IDs and what you saw, so you can later explain why this invoice didn’t go through Peppol.

Once your customer is on Peppol

From then on, send new invoices via Peppol. Invoices you issued another way in the meantime don’t need to be resent retroactively as structured e-invoices; the same FAQ says so explicitly.

Working for many clients? Check the whole client list in one go. For each client you see whether 0208, 9925, both or neither works.

Frequently asked questions

May I email a PDF if my customer isn’t on Peppol?: Yes, if your customer agrees and you agree on a secure channel. Without that agreement, use another way, such as paper.
Do I have to resend that invoice via Peppol later?: No. Once your customer’s system works, send new invoices via Peppol. Earlier invoices don’t need to be resent.
My software can’t find my customer, but they say they’re on Peppol. Who is right?: Often both: they are registered under the other ID. Check 0208 and 9925 and use the one that receives invoices.
Am I at fault if my customer can’t receive?: According to the official FAQ, the invoice you issue another way fulfils your invoicing obligation. The penalty risk lies with the customer.