Peppol BIS Billing 3.0 supports both UBL invoices and UBL credit notes. In a credit note, the document type indicates that the amounts reverse an earlier invoice; minus signs do not turn an invoice into a credit note. A negative invoice is different: it uses the Invoice document type with negative quantities and amounts to reverse a positive invoice. A credit note may contain negative amounts only when it reverses a negative invoice.

The message uses OASIS UBL 2.1 and ISO/IEC 19757-3 Schematron to automate document validation.

More information on Peppol BIS Billing 3 credit note.

More information on Peppol message types.