Methods and systems for processing messages at a first network node in a mobile communications network are disclosed. A first message relating to a communication in a mobile communications network that includes a called directory number is received. A lookup is performed in a first database based on the called directory number to determine whether a called party has been ported out of a first network and to determine a migration status of the called party. In response to determining that the called party has been ported out of the first network, a first reply message is formulated including first routing information from the first database that indicates a second network to which the called party has been ported. If the called party has not been ported out, a second reply message is formulated including second routing information from the first database that corresponds to the determined migration status.