Abstract: A system and method for straight through payment processing when the merchant is known but the merchant's payment card acquirer is unknown. Payment instructions from a payee to the merchant are normalized for a target acquirer system which is selected either at random, based on business logic and data, or based on successful past straight through payments. Payments are attempted for each acquirer successively until a successful payment notification is received. The link to the merchant and acquirer is then saved for subsequent straight through payments to that merchant.