Abstract: Calls are transferred from a first call to a second call in a trunked digital radio communications system that includes a first transmitting user terminal that communicates with a receiving user terminal or group of user terminals in the first call over a first working channel via a base station. A second call is transmitted from a second transmitting user terminal to the base station over a second working channel, that identifies the receiving terminal. Transfer data is transmitted from the base station to the receiving terminal or group of user terminals in the first call on the first working channel, the transfer data identifying the second call and the second working channel. The transfer data is detected in the first call on the first working channel at the receiving user terminal and the receiving user terminal transfers to the second call on the second working channel based upon the transfer data.