AT&T Merlin Legend 10BS User Manual page 81

Features
NOTE:
For Step 2, if you have programmed an outside
Auto Dial button with a specific account code
followed by #, you can press the button whenever
you need to enter the code. (See Auto Dial.)
If you are using account codes on a conference
call, follow Steps 1 through 5 above and press
Conference. When adding participants, repeat
steps 1, 2, 3, and 5 and press Conference again.
This associates an account code with each
participant.
To Enter or Change an Account Code
During a Call
1. Press the programmed Account Code button, or press
the programmed Feature button and dial 82.
2. Dial the account code followed by #.
5-4
Account Code Entry