What is Peppol? How the network works

Peppol gives trading partners a common way to exchange structured documents, such as invoices and orders. Structured means that the receiving software can read the individual fields, such as an invoice number, tax amount and payment reference, instead of someone copying them from a PDF.

There are three parts to this: specifications for the documents, a network for delivering them, and agreements governing the organisations that operate it. OpenPeppol is the non-profit association that maintains the framework. Peppol began as a European project in 2008 and is now used internationally.

A business does not connect to the network on its own, and it does not need to become an OpenPeppol member. It takes part through a service provider, and the connection is often built into its accounting software.

Because each business takes part through a provider, every exchange involves four parties: the sender, the recipient and their two providers. This is called the four-corner model. It lets the sender and the recipient choose different providers.

Following the numbers in the diagram, an invoice travels like this:

1. Sender. Your accounting or ERP system prepares the invoice.
2. Sending Access Point. Your provider checks the document and finds the recipient's receiving service.
3. Receiving Access Point. The recipient's provider receives the document over the Peppol network.
4. Recipient. The provider delivers it to your customer's system for processing.

An Access Point, often shortened to AP, is the provider's service that connects to other Access Points. The network's AS4 transport profile secures the exchange between them. How your own software connects to its provider depends on the service you choose.

Before sending, the sending Access Point must find out where to deliver, shown by the dashed path in the diagram. The Service Metadata Locator (SML) helps find the recipient's Service Metadata Publisher (SMP). The SMP publishes receiving capabilities: supported document types, business processes and delivery endpoints. For this lookup to work, the sender needs two things: the recipient's Peppol ID and a document specification the recipient supports. The next two sections explain each of them.

Explore the service providers and their supervising Peppol Authorities.

A Peppol ID is the address that the lookup uses to find a participant. It combines an identifier scheme with a value, commonly written as scheme:value. The scheme tells software what kind of identifier the value represents. Depending on the registration, this can be a company identifier or a Global Location Number (GLN).

An organisation can have more than one participant ID. A company number on its own does not tell you which scheme to use or which documents a particular registration can receive. Ask your trading partner for its receiving details if you are unsure.

Search the published Directory listings by name or identifier. Directory publication is voluntary: a missing result does not prove that a company cannot receive Peppol documents. Confirm current receiving capabilities through your provider before sending.

The second thing the sender needs is a document the recipient can receive. Peppol covers more than invoices: the official catalogue includes registrations for credit notes, orders, order responses, catalogues, despatch advice and other business documents. A recipient's supported specifications determine what you can send to it.

Three terms help separate the layers:

• UBL (Universal Business Language) provides an XML vocabulary for structured business documents.
• BIS (Business Interoperability Specifications) defines how documents are used and checked in a business process. Peppol BIS Billing 3.0 covers invoices and credit notes using UBL.
• PINT (Peppol International) provides a shared billing model that can be specialised for different jurisdictions. Check the applicable specialisation rather than assuming every PINT invoice has identical requirements.

An invoice is a business document; a specification defines its requirements; a technical document type identifier identifies a particular supported registration. Those are related concepts, but they answer different questions.

Explore the official categories, active document types and separate explanations.

Knowing how Peppol works still leaves the question of whether you have to use it. Peppol is used for business-to-government and business-to-business exchanges across multiple regions. A country's use of Peppol does not, by itself, mean that every business must use it for every invoice.

Check the rules for the parties, transaction and date involved. An electronic invoicing requirement, a requirement to use a particular delivery network and a tax-reporting obligation are different requirements. Cross-border delivery also does not automatically satisfy local reporting duties.

Explore countries, Directory coverage and sourced country guidance. The map distinguishes the available reference information from participant counts; neither a Directory listing nor a large count establishes a legal obligation.

Since businesses take part through a provider, start by asking your accounting or ERP supplier whether your current product supports Peppol sending, receiving or both. Some products include a connection; others use an integration or a separate provider.

Whichever Access Point you choose, check the following:

• Which countries and document specifications you need to exchange with your trading partners.
• How your receiving ID will be registered and how it will be managed if you change providers.
• What the price includes: sending, receiving, integrations, document conversion and support.
• How you will see validation errors, delivery information and documents that need attention.

Prepare a valid document and confirm your customer's receiving details before your first exchange. Keep the information your own bookkeeping process needs; network delivery is one part of handling an invoice.