A technique for managing an automatically established roaming agreement between two IMS networks (102, 104) is described, wherein one IMS network (102) supports multiple proxy nodes (302, 106) at the network edge towards the other IMS network (104). A method embodiment of the technique is performed in an I-CSCF (302) of the first IMS network (102) and comprises the steps of receiving (316) a registration request of an UE (306) via a second IMS network (104); sending (324) a roaming information request indicating the second IMS network (104) to a HSS (110) associated with the first IMS network (102); receiving (326) from the HSS (110) a roaming information answer indicating information related to the roaming agreement, and forwarding (328), based on the roaming information answer, the registration request to a second I-CSCF (106) of the first IMS network (102) managing the roaming agreement.