How Peppol works — the 4-corner model
Peppol uses a 4-corner model. The sender (corner 1) hands a document to their Access Point (corner 2), which looks up the receiver's Access Point (corner 3) via SML/SMP and delivers it over AS4; corner 3 passes it to the receiver (corner 4).
The four corners
- Corner 1 — the sender. Your ERP, accounting tool or the Verteco portal produces a structured document (UBL / Peppol BIS).
- Corner 2 — the sender’s Access Point. Validates the document, discovers the receiver and delivers it over the secure AS4 protocol.
- Corner 3 — the receiver’s Access Point. Accepts the transmission, acknowledges it and hands the document over.
- Corner 4 — the receiver. Gets the document in their software or portal.
Discovery: SML and SMP
Every Peppol ID is registered in the SML (Service Metadata Locator), a DNS-based registry pointing to the participant’s SMP (Service Metadata Publisher). The SMP lists which document types the participant can receive and which Access Point serves them. This is how any sender can reach any receiver without prior agreement — try it yourself with the Peppol ID lookup.
Delivery guarantees
Transport is encrypted (AS4 over TLS with signed messages using Peppol PKI certificates), and every transmission is acknowledged. If delivery fails, the sending Access Point retries — the sender always knows whether the document arrived.
Updated: August 29, 2026