Peppol eInvoicing

Peppol (Pan European Public Procurement Online) enables European trading partners to easily exchange standards-based electronic documents with any European public sector buyer in their procurement processes. The OpenPeppol Network is based on a 4-corner model which offers interoperable standards for the entire electronic procurement cycle from e-Orders, e-Advance Shipping Notes, e-Invoices, eCatalogues to Message Level Responses, etc.  

Visit https://peppol.eu/ for more information.