Use the flash feature on your home phone to initiate a three-way conference call.
INSTRUCTIONS & INFO
During a call, press the Talk/Flash key.
Wait until a dial tone can be heard, then enter the number of the second party to add to the call.
With both calls on the line, press the Talk/Flash key to initiate three-way calling. Note: If the second caller does not respond, press the Talk/Flash key to disconnect and return to the first call.