Techniques for managing a registration of a roaming user terminal (116) in its IMS home network (102) based on a roaming agreement between the visited IMS network (104) and the home IMS network (102) are described. According to one embodiment of the invention, a method for managing user registrations in the first IMS network (102) is provided. The method may be performed in an I-CSCF (106) of the first IMS network and comprises the steps of determining a status change in an automatically established roaming agreement with the second IMS network; and sending, based on the determination result, roaming status update information (204) to an HSS (110) associated with the first IMS network for initiating a registration update of the user.