Solution : https://service.sap.com/sap/support/notes/303358 (SAP Service marketplace login required)
Key words :
additional key words intercompany, order-related billing document, cross-company code sales, sales order item, external billing document, attached advance correction, cross-company, intercompany billing, billing 'b', status 'rel'
Related Notes :
| 183457 | SAPKKA12:Status 'Final billing' cannot be set |
| 95145 | 'Final billing' status for cross-company processing |