One aspect can provide a system and method for enforcing a single-domain registration of a user equipment (UE) roaming across different provider networks. During operation, the system can receive, at a subscriber-management entity (SME) from a first service node within a first provider's network, a location-update message associated with the UE. The system can identify a second service node within a second provider's network with which the UE has a previous registration and query a subscriber-information database to determine whether a single-domain-registration feature is enabled at the SME for the UE. In response to determining that the single-domain-registration feature is enabled, the system can send a location-cancellation message to the second service node to cause the second service node to cancel the previous registration of the UE and register the UE at the SME.