All Sonic Fusion Voice lines support 3-way calling.
Steps to create a 3-way call:
- Connect with the first party.
- Press "Flash" (or "Link", or briefly hold down the on-hook switch.)
- Wait for dial tone.
- Dial the second number.
- When the second party answers, flash again to reconnect the first party.
If the second part does not answer or you reach a busy signal pressing flash will disconnect and return you to the first call.
When you are ready to disconnect the second party, simply hit flash again.