If included in your phone package, to activate three-way calling:
While on a call, press the “flash” key or switch hook with a quick tap. You’ll hear three short beeps, followed by the dial tone- this has simply placed your first call on hold.
Next, dial the number of the person you’d like to add to the conversation/call. When they answer, you’ll have the opportunity to let them know in private that you’re adding them to your present call before they join the three-way call.
Finally, press the “flash” key or switch hook with a quick tap to return to your first call and connect the new person to your original call.
To disconnect from a three-way call:
To disconnect the third party from the call, press the flash key.