This invention is directed to a modularized interface for connecting a plug-in electric vehicle to the energy grid. For use with public or semi-public outlets, the modularized interface comprises a module and a smart socket, where the module is integrated within or capable of being connected to, the vehicle's charging interface. The module is normally disabled, but is enabled only after the end user is authenticated, the smart socket and its associated meter have been identified, and the module and the end user's account with the local utility are validated. The module meters the energy consumption, and, when the module is disconnected from the smart socket, indicating termination of the charging session, the metered data is communicated to the utility for updating the end user's account, and the module is disabled. The module is also capable of use with conventional outlets located, for example, in private residences.