Hermes Is Gone: What Changes When a Belgian Buyer Is Not on Peppol
Hermes closed on 31 December 2025. Belgian companies are no longer pre-registered on Peppol, so an unreachable buyer is now a real and visible failure.
The short answer
Hermes was decommissioned on 31 December 2025, with read-only access until March 2026. It used to pre-register every Belgian company on Peppol so anyone could be reached by default. That is no longer true.
A Belgian buyer who has not appointed a Peppol service provider is now genuinely unreachable, and a send to them fails at lookup. That is a correct outcome, not a fault in your system — and telling the two apart is the whole point of this article.
What Hermes was, and why it existed
When Belgium pushed B2G e-invoicing out to the full public sector, it faced an ordinary chicken-and-egg problem: suppliers could not send structured invoices to buyers who were not on the network, and buyers had no reason to join until suppliers were sending.
Hermes cut the knot. BOSA operated an SMP in which Belgian companies were pre-registered by default, using their enterprise number. Anyone could address any Belgian business on Peppol. If the recipient had no real capability behind the registration, Hermes converted the invoice and forwarded it by email.
It worked, and it did what a transitional mechanism is supposed to do: it made the network usable before the network existed.
Why it was switched off
Because the transition finished. With the B2B mandate live from 1 January 2026, every VAT-registered Belgian business has to be able to receive structured invoices properly. A fallback that quietly downgrades an invoice to a PDF is no longer a safety net — it is a way for a business to stay non-compliant without noticing.
There is also a data-quality argument. A directory in which most entries are placeholders is a directory you cannot trust. Removing the placeholders means a successful lookup now tells you something real: this participant has a provider and can genuinely receive.
What actually changed for senders
A missing recipient is now visible. Before, a send to an unprepared Belgian buyer succeeded and arrived as an email. Now the SMP lookup returns nothing and the send does not happen.
"Not found" has become the common case, not the rare one. Around a genuine deadline, plenty of small Belgian businesses had not yet appointed a provider. Systems that treat lookup failure as an exception worth paging someone about will page a lot.
The diagnosis is usually not a typo. This matters for the message you show. "Verify the Peppol ID is correct" sends the sender hunting for a mistake in a number that is fine. The likelier cause is that the buyer has not onboarded. Say that.
We changed our own wording for exactly this reason — a generic not-found message was actively misleading in the one market where the cause is almost always something else.
How to diagnose it properly
- Check the identifier format. Ten digits, scheme
0208, with a valid mod-97 check digit. A wrong check digit is the one case where it is your data. - Do the SMP lookup directly for
0208:<number>. If it resolves, the buyer has a provider and the problem is elsewhere — capability, document type, or your own send path. - If it does not resolve, ask the buyer who their provider is. They may have appointed one that has not completed registration, which looks identical from outside.
- Do not fall back to email silently. That reintroduces exactly the ambiguity Hermes was retired to remove. Surface it, and let a human decide.
What to build into your product
- A pre-send reachability check. Resolve the recipient before you let a user press send, not after. A validation message beats a delivery failure.
- A message that names the likely cause. "This recipient is not registered on Peppol — Belgium retired the Hermes SMP on 31 December 2025, so Belgian companies are no longer pre-registered. The buyer needs to appoint a provider."
- A distinction between three states — not registered, registered but cannot receive this document type, and a genuine transport failure. They look the same to a naive integration and need three different responses.
- No automatic PDF fallback without an explicit human decision.
Related reading
- Belgium e-invoicing compliance — scope, format, penalties, 2028
- Belgian enterprise number on Peppol — rule out the identifier first
- Belgium e-invoicing for foreign companies
- How to choose a Peppol access point — what to ask about lookup and error handling
Primary sources: einvoice.belgium.be · FPS BOSA, Belgian Peppol Authority · European Commission — eInvoicing in Belgium
Frequently asked questions
- When did Hermes shut down?
- Hermes was decommissioned on 31 December 2025, with read-only access retained until March 2026. It is now fully retired.
- What did Hermes actually do?
- BOSA pre-registered Belgian companies in the Hermes SMP so they were reachable on Peppol by default, and forwarded anything undeliverable to the recipient by email. It made every Belgian business addressable without them having chosen a provider.
- What replaces Hermes?
- Nothing replaces it, by design. Belgian businesses now appoint a Peppol service provider, which registers them in its own SMP. There is no longer a default fallback.
- Why does my invoice to a Belgian company fail lookup?
- Most likely the buyer has not appointed a Peppol service provider, so there is no SMP record to resolve. Check the enterprise number is correct first, then ask the buyer who their provider is.
About Dr. Syed Raza
Dr. Syed Raza is an IT Enterprise Architect at ClayDesk LLC and leads the GoRoute platform. He works across Peppol Access Point and SMP infrastructure, PINT jurisdictions (Oman, AU/NZ, EU, JP, MY, SG), and national CTC regimes, translating regulatory detail into production-grade e-invoicing systems.
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