As of Release 4.0A you can define the permitted alternative payees/payers in the vendor/customer master record.
As of Release 4.5A you can transfer the alternative payees/payers into the vendor/customer master records per batch input using programs RFBIKR00 and RFBIDE00.
You can transfer the alternative payees into the R/3 System using program RFBIKR00 and structure BLFZA.
You can transfer the alternative payers into the R/3 System using program RFBIDE00 and structure BKNZA.
You can define the alternative payees/payers allowed both independent of company code and dependent on company code.
The BUKRS (company code) field is left blank in tables LFZA or KNZA with cross-company code alternative payees/payers.