A method for a single radio voice continuity, SRVCC, handover, comprising: before handing over by SRVCC a voice service call from a first packet switched PS network to a second cirtcuit switched CS network, when creating an original call between a calling party and a called party in the first network, the calling party transmitting (S11-S12) a list of codec types supported by itself to an Access Transfer Control Function, ATCF; the ATCF adjusting the list of codec types supported by the calling party according to codec types supported by a media gateway, MGW through which the call will be established in the CS network by: comparing the list of codec types supported by the calling party with the list of codec types supported by the MGW, and in a condition of knowing that the codec types supported by the called party includes at least one codec type supported by the MGW, deleting the codec types not supported by the MGW from the list of codec types supported by the calling party, leaving only codec types supported by the MGW, and forwarding (S16-S17) the adjusted list of codec types to the called party; and, the called party selecting at least one codec type from the adjusted list of codec types, and informing (S18-S112) the calling party of the selected codec type, wherein the codec type selected by the called party is the media codec type negotiated by the calling party and the called party; in a process of handing over by SRVCC the voice service call from the first network to the second network, the calling party and the called party performing (S21-S25) communication based on the media codec type negotiated by the calling party and the called party; wherein both the calling party and the called party are SRVCC users. before handing over by SRVCC a voice service call from a first packet switched PS network to a second cirtcuit switched CS network, when creating an original call between a calling party and a called party in the first network, the calling party transmitting (S11-S12) a list of codec types supported by itself to an Access Transfer Control Function, ATCF; the ATCF adjusting the list of codec types supported by the calling party according to codec types supported by a media gateway, MGW through which the call will be established in the CS network by: comparing the list of codec types supported by the calling party with the list of codec types supported by the MGW, and in a condition of knowing that the codec types supported by the called party includes at least one codec type supported by the MGW, deleting the codec types not supported by the MGW from the list of codec types supported by the calling party, leaving only codec types supported by the MGW, and forwarding (S16-S17) the adjusted list of codec types to the called party; and, the called party selecting at least one codec type from the adjusted list of codec types, and informing (S18-S112) the calling party of the selected codec type, wherein the codec type selected by the called party is the media codec type negotiated by the calling party and the called party; in a process of handing over by SRVCC the voice service call from the first network to the second network, the calling party and the called party performing (S21-S25) communication based on the media codec type negotiated by the calling party and the called party; wherein both the calling party and the called party are SRVCC users.