How to search and verify a participant in the Peppol network?
Short answer
Verification of a participant in the Peppol network has four layers: the public Peppol Directory for human-readable search, a technical lookup via SML and SMP to determine whether the participant identifier is published and routable, a check of document capabilities (what types of documents it can accept) and, finally, the matching of the result with the partner's own master data. Neither the Directory nor the lookup itself is a commercial confirmation that you are sending the invoice to the correct entity.
Service Metadata Locator
A central lookup layer working similarly to DNS. It does not tell what the participant can accept — it just helps to find out which SMP has metadata about it. It does not store invoices or accounting content.
Service Metadata Publisher
It publishes the content itself: what types of documents the participant receives and the technical details of delivery — endpoint, supported processes and transport settings. If this metadata is out of date, delivery will fail even with error-free XML.
Peppol Directory
Voluntarily filled, human-readable directory for an indicative search for a partner by name, country or identifier. It is updated asynchronously — a subscriber can technically be published and yet not appear in the Directory (or vice versa).
SML will point to SMP, Directory is extra
The order of the technical search is: participant identifier → SML finds the corresponding SMP → SMP tells what the participant receives and where the document is to be delivered. Directory is a parallel, voluntary directory above this — convenient for reference, not binding proof of deliverability.
Conclusion
OpenPeppol — Interoperability Framework · OpenPeppol — Service Metadata Locator · OpenPeppol — Peppol Directory · VPDS of the Financial Administration of the Slovak Republic
Not legal advice. Machine-translated answer, not yet manually reviewed. For the exact wording, see the Slovak original.