What is Peppol?
By way of background, Peppol is the name of the Network and Business Interoperability Specifications that OpenPeppol provide, as part of a comprehensive Peppol Interoperability Framework, which includes legal agreements, governance and compliance measures. Peppol integrates business processes by standardising the way information is structured and exchanged under e-invoicing. Peppol enables trading partners to exchange standards-based electronic documents over the Peppol network based on a four-corner model.
Source Avalara