The present document gives the stage 3 description of the Multicall (MC) supplementary service. The present document specifies the procedures used by the radio interface for normal operation@ registration and interrogation of the Multicall supplementary service. Provision@ withdrawal@ erasure@ activation and deactivation of supplementary services is an administrative matter between the mobile subscriber and the service provider and causes no signalling on the radio interface. 3GPP TS 24.010 describes the general aspects of the specification of supplementary services at the layer 3 radio interface. 3GPP TS 24.080 specifies the formats and coding for the supplementary services. Definitions and descriptions of supplementary services are given in 3GPP TS 22.004@ 3GPP TS 22.072@ 3GPP TS 22.08x@ 3GPP TS 22.09x-series and 3GPP TS 22.135. 3GPP TS 22.135 is related specifically to the Multicall supplementary service. The technical realisation of supplementary services are described in 3GPP TS 23.011@ 3GPP TS 23.072@ 3GPP TS 23.08x@ 23.09x-series and 3GPP TS 23.135. 3GPP TS 23.135 is related specifically to the Multicall supplementary service. The procedures for Call Control and Mobility Management at the layer 3 radio interface are defined in 3GPP TS 24.007 and 3GPP TS 24.008. The following supplementary services are described in the present document: - Multicall (MC) (see clause 4).