Methods and systems for routing payment transactions electronically involve interrogating by computer logic each payment transaction received by a payments interface processor to identify a payment destination and a payment source and to determine, according to pre-defined parameters, whether the payment transaction is eligible for processing via an internal payment transaction processor of the financial institution that minimizes processing costs. Eligible payment transactions may be routed, for example, to an internal debit or credit card processor or ACH processor, and ineligible payment transactions may be routed to external card processing networks.