A method is provided of informing mobile user terminals (12) camped on a cell of a base station (8) of a radio telecommunications network that a service is unavailable, such that a mobile user terminal (12) desirous of said service is handed over to another cell which provides said service. The method comprises informing the terminals (12) that selectably at least one of circuit-switched services (4) and packet-switched services (6) are unavailable.