To start a 3-way or N-way call on a Yealink phone, start by placing (or answering) the first call. When you are on the phone, desk phones will display a Conference button on a softkey below the screen.
Press the conference button, and dial the additional party.
When the party answers, press the Conference key to join the new call to the original call.
The Conference button on a cordless phone is accessed using the Options softkey which opens a menu containing this option.
Yealink SIP-T21P-E2, Yealink W52P / W52H, Yealink SIP-T48G, Yealink SIP-T29G, Yealink CP860 (EOL), Yealink CP920, Yealink CP960, Yealink W60P / W56H, Yealink CP930W, Yealink SIP-T43U, Yealink SIP-T46U, EXP43