Bank Details in Open Items
You can specify the bank details of the business partner in the open items simply by entering a bank type in the item. The bank type is a feature that you can assign freely for all of your customer or vendor's banks. If a bank type is specified in the item, a bank with the same bank type is selected from the master record for payment (see the figure below).
If there are several banks specified in the customer/vendor master record, some with and some without a bank type, the system first checks those banks in the master record that do not have a bank type for purposes of paying documents that also have no bank type specified. Banks with a bank type are only used if the master record contains none of the former type.
If you want to specify the paying house bank in the item, you can enter the appropriate bank ID there (see the figure above).