A method for performing variable rate speech coding in the speech codec comprising a plurality of speech codec modes operating at different bit rates, the speech encoded by said speech codec being arranged for transmission in a telecommunications network. Information on an active speech codec mode set to be supported is received from the telecommunications network, in response to which the supported speech codec modes that correspond to the active codec mode set determined in the telecommunications network will be activated. Thereafter, speech signals to be applied to the speech codec are encoded with the activated speech codec modes such that the speech codec mode of the substantially lowest bit rate is adapted to the speech frames comprised by the speech signals such that in view of the channel conditions in the telecommunications network the level of residual error in coding will be substantially minimized at the same time.