Method for providing multimedia message service, MMS, interoperability between a first mobile telephone service provider and a second mobile telephone service provider, the method comprising: receiving an MMS message from the first mobile telephone service provider; querying a telephone number portability database that identifies a corresponding mobile telephone service provider for each of a plurality of telephone numbers to determine an identity of the second mobile telephone, service provider to which the MMS message is intended to be sent; querying a carrier profile repository to access a carrier profile for the second mobile telephone service provider, the carrier profile including information regarding an MMS format acceptable to the second mobile telephone service provider; sending the MMS message received from the first mobile telephone service provider to the second mobile telephone service provider when the second mobile telephone service provider can accept the received MMS message as is; if the second mobile telephone service provider cannot accept the MMS message as is, iterating through entries in the carrier profile in a ranked or weighted manner to determine if a transcoding operation is applicable to the current situation and, if so, performing the appropriate transcoding operation and sending the resulting transcoded MMS message to the second mobile telephone service provider; and if a transcoding operation is not applicable to the current situation, sending a informational short message service, SMS, message to an SMS Center, SMSC, of the second mobile telephone service provider, and alternatively employing a best possible routing model and delivering the MMS message to a legacy facility of the second mobile telephone service provider. receiving an MMS message from the first mobile telephone service provider; querying a telephone number portability database that identifies a corresponding mobile telephone service provider for each of a plurality of telephone numbers to determine an identity of the second mobile telephone, service provider to which the MMS message is intended to be sent; querying a carrier profile repository to access a carrier profile for the second mobile telephone service provider, the carrier profile including information regarding an MMS format acceptable to the second mobile telephone service provider; sending the MMS message received from the first mobile telephone service provider to the second mobile telephone service provider when the second mobile telephone service provider can accept the received MMS message as is; if the second mobile telephone service provider cannot accept the MMS message as is, iterating through entries in the carrier profile in a ranked or weighted manner to determine if a transcoding operation is applicable to the current situation and, if so, performing the appropriate transcoding operation and sending the resulting transcoded MMS message to the second mobile telephone service provider; and if a transcoding operation is not applicable to the current situation, sending a informational short message service, SMS, message to an SMS Center, SMSC, of the second mobile telephone service provider, and alternatively employing a best possible routing model and delivering the MMS message to a legacy facility of the second mobile telephone service provider.