Account Invoice Alternate Payer

On any invoice or bill you get a new "Alternate Payer" field right after the main Partner field. It can only be changed while the document is still in draft; once posted it becomes read-only.

When you set an alternate payer, the payment terms lines of the invoice are automatically assigned to that partner, and the bank partner used for payment is switched to the alternate payer for outbound (vendor bill) documents.

The outstanding credits/debits widget shown on the invoice is recalculated so it looks for open items belonging to the alternate payer instead of the commercial partner, helping you see what that partner still owes or is owed.

When you register a payment from an invoice, the payment partner defaults to the alternate payer (or the commercial partner if none is set). The same happens when creating a payment directly from the invoice context.

A small safeguard prevents the payment-term lines from being silently reassigned back to the main partner when only the partner is changed on those lines.