How does the Peppol network work?
Short answer
Similar to mobile operators: each participant has its own provider (e-invoicing delivery-service provider) and the providers securely exchange the document according to common Peppol rules (four-arm model). Participant identifiers, SML and SMP are used to search for the recipient. In Slovakia, it is also required by § 76a of the VAT Act, which refers to the technical standard Peppol BIS/EN 16931.
Four-arm model
Supplier → its provider → customer provider → customer. The "join once, reach all" principle.
Recipient search
The network first finds out through directory services (SML, SMP) whether the recipient exists in the network, what documents he can accept and where his technical data is.
Validation
The document being sent must meet the rules of the Peppol BIS format (based on the EN 16931 standard). Malformed XML can be stopped before delivery.
States and evidence
It is important for the company to track not only the shipment, but also the receipt, rejection, errors, retries and audit trail.
Conclusion
OpenPeppol — Interoperability Framework · Financial Administration — e-invoice
Not legal advice. Machine-translated answer, not yet manually reviewed. For the exact wording, see the Slovak original.