Business Interoperability Specifications (BIS)
Peppol has developed the Business Interoperability Specifications (BIS) for common eProcurement processes to standardise electronic documents exchanged and validated through an open and secure network, between sending and receiving Access Points for public sector buyers and their suppliers across Europe and beyond.
Cit. https://peppol.eu/what-is-peppol/peppol-profiles-specifications/
If you manage a BIS that is not listed here, feel free to contact us at peppol@a-cube.io to explain your needs.
PEPPOL BIS Billing
This PEPPOL BIS provides a set of specifications for implementing a PEPPOL business process.
You can find the official documentation here.