During the payment system will always pick the first House Bank and Account ID that is suitable for the payment.
The House Bank is picked automatically regarding your customizing settings in Customer/Vendor Master Data (the first system choice) and in transaction FBZP -> 'Bank determination'.
In FBZP you should define a ranking order, bank accounts and available amounts for the payment methods.
For the assignment of of House Bank and a Payment Method go to transaction FBZP > Bank Determination:
- Choose company code;
- Ranking order: Make sure you have currency + payment method assigned for house bank you intend to use;
- Bank accounts: Make sure that you have payment method assigned for Currency /House Bank /Account ID /Bank Sub account;
- Available amounts: Make sure that "Available for outgoing payment" is filled for House Bank /Account ID from (3) and Currency.
By standard you will not be able to change the rank order you should use a BTE in order to achieve your business requirements.
Consider the usage of the following business transaction event (BTE, in another words OPEN_FI):
- 00001120 DOCUMENT POSTING: Field substitution header/items
- 00001130 POST DOCUMENT: SAP-internal field substitution
- 00001810 PAYMENT PROGRAM: Individual bank determination
- 00001025 POST DOCUMENT: Final checks completed
- 00001030 POST DOCUMENT: Posting of standard data
For additional documentation about this can be found in transaction FIBF. There you can use the info system for processes (Environment > Infosystem (Processes) and do a search for selection attribute FI.
To change the House Bank order the event 1810 can be used.