Abstract: A one-time transaction token is requested by a user from a payment provider system for a payment transaction initiated by the user. The one-time transaction token is stored by the payment provider system. The one-time transaction token is provided to the user, and the user provides the one-time transaction token to a transaction processing system and from there to an acquirer processing system. Based on the one-time transaction token received, the acquirer processing system identifies the payment provider system which generated the one-time transaction token and transmits it to the identified payment provider system. Upon receipt of the one-time transaction token, the identified payment provider system validates the received one-time transaction token with the one-time transaction token previously generated by the identified payment provider system.