Infrastructure
Peppol
Definition
Peppol (Pan-European Public Procurement On-Line) is an international network and infrastructure for the secure electronic exchange of business documents, especially invoices and orders. It is based on a four-corner model with Access Points, a central directory (SMP/SML), and standardised document formats (e.g., Peppol BIS Billing 3.0 based on UBL). In Germany, KoSIT operates the Peppol directory.
Background & context
Peppol is not software but a rulebook and an open infrastructure for the secure, standardised exchange of electronic business documents. It works on the four-corner model: the sender (corner 1) hands its document to its Access Point (corner 2), which forwards it over the Peppol network to the recipient's Access Point (corner 3), which finally delivers it to the recipient (corner 4). Central to this are the Service Metadata Locator (SML) and the Service Metadata Publishers (SMP), which record which participant can receive which document types via which Access Point. Each participant has a unique Peppol Participant ID (e.g. a Leitweg-ID or VAT ID with a scheme prefix). The exchanged documents follow the Peppol BIS (Business Interoperability Specifications) — for invoices, Peppol BIS Billing 3.0 based on UBL. In Germany, KoSIT acts as the Peppol Authority and operates the national infrastructure; the ZRE and OZG-RE portals are reachable via Peppol.
In practice — a worked example
A supplier wants to send an invoice to a federal authority via Peppol. Its software hands the XRechnung (UBL) to its Access Point. The Access Point looks up in the SMP — using the recipient Participant ID (derived from the Leitweg-ID) — which Access Point is responsible for ZRE, and delivers the document there. The entire transport is signed and encrypted; the sender receives a technical acknowledgement (MLR/Message Level Response). The advantage: senders and recipients do not need to set up bilateral connections — once connected to Peppol, you reach all other participants.
Common mistakes
- •Peppol only transports; it does not fully check business logic — an invoice delivered via Peppol can still fail BR-DE rules.
- •A wrong or unregistered Participant ID means no Access Point is found and delivery fails.
- •You cannot use Peppol directly — sending and receiving always go through a certified Access Point (self-operated or via a service provider).
Frequently asked questions
What is the four-corner model?
It describes the Peppol exchange via four parties: sender, its Access Point, the recipient's Access Point, and the recipient. The two Access Points communicate in a standardised way, so no direct connection between sender and recipient is needed.
Do I need Peppol for XRechnung?
Not necessarily. Peppol is one of several transmission channels for XRechnung (alongside web form, email upload, De-Mail). For high volumes and automation, however, Peppol is the preferred channel.
What are SML and SMP?
The Service Metadata Locator (SML) is the central DNS-based directory that points to the correct Service Metadata Publisher (SMP). The SMP holds a participant's specific receiving capabilities and endpoints.