Press the Cnfrnc soft key on a Model 430 (Model 601: the Conference key) to create a new call. The active call will automatically be placed on hold.
Dial the phone number of the second party or use the arrow keys to access speed dial numbers, or missed, placed and received call lists. From one of these lists press the Dial soft key.
When the second party answers, press the Cnfrnce soft key (Model 601: the Conference key) again to join all parties in the conference, or press the Split soft key to put the first call on hold and keep the second call as the active call.