This technique forwards the first incoming call to the answering service once your line is busy. You no longer have to worry about using the phone when you are expecting an important call. Call forward busy sends the first incoming call to the answering service once your line is being used.
Dial ★ 9 0. Listen for a special dial tone, dial the number that you want your calls forwarded to, followed by the #sign and hang up.
Dial ★ 9 1 and listen for a confirmation tone.
For Call Waiting customers, Call Forwarding Busy will forward your incoming calls when you’re already on the line with two callers or if you have temporarily deactivated Call Waiting. Repeat the first three steps to change your forwarding number.