Systems and methods for person-to-person and person-to-merchant remittances from a person having a closed loop system account to merchants who are not members of the closed loop system. In an embodiment, a payment gateway computer receives a remittance transaction request from a payment services provider (PSP) computer associated with a closed-loop system, maps an alias identifier into a shadow account number assigned to the sender in an open-loop payment authorization system, determines that the alias identifier mapped into a valid shadow account number, debits a stored value account for the remittance transaction amount, credits a shadow account in the open-loop payment authorization system for the remittance transaction amount, generates an authorization request for an open-loop payment transaction and transmits it to the open-loop payment authorization system, receives an authorization response from the open-loop payment authorization system, and transmits an approval response.