According to https://docs.peppol.eu/poacc/billing/3.0/syntax/ubl-invoice/cac-OrderReference/ the cbc:ID in the Order Reference should be the PO number of the customer. closes odoo/odoo#84988 X-original-commit: cd4145366ae1b1401c3f8a9378ef00f8208c889f Signed-off-by: Laurent Smet <las@odoo.com> Signed-off-by: William André (wan) <wan@odoo.com>