Methods and systems for routing payment transactions electronically for multinational vendors in a transnational business environment in which an integrated payments platform processor is used in receiving payment transactions related to a plurality of different countries by a financial institution for online purchases. Each payment transaction is interrogated, using the integrated payments platform processor, to identify the payment transaction as an internal type of transaction or an external type of transaction and a country to which the payment transaction relates. Internal types of transactions are routed to an internal transaction processing path and external types of transactions to an external processing path, and the financial institution may arrange settlement of each payment transaction likewise using the processor.