System and methods for providing multimedia message service (MMS) interoperability between an initiating carrier and a destination carrier. A transcoding facility receives an MMS message from an initiating carrier and accesses a number portability database to determine an identity of a destination carrier to which the MMS message is intended to be sent and a carrier profile repository to obtain a carrier profile for the destination carrier, the carrier profile including information regarding an MMS format acceptable to the destination carrier. The transcoding facility determines, based on the carrier profile and a format of the MMS message received from the initiating carrier, whether the format of the MMS message received from the initiating carrier must be modified to be effectively received by the destination carrier and, if so, transcodes the MMS message in accordance with the carrier profile to generate a transcoded MMS message, and thereafter sends one of (i) the MMS message received from the initiating carrier and (ii) the transcoded MMS message to the destination carrier.