The following instructions apply to Airtel landline phones.
To set/change your secret code:
Dial 123-xxxx-yyyy where xxxx is your old code and yyyy the new code. The default code is 1234 if you are setting your code for the first time. Note that your code cannot be 1234.
Dial 124 followed by your 4 digit code and then dial the appropriate locking digit from the table below. For example, to lock STD/ISD calls, dial 124-xxxx-1.
xLocking Digit Status
0 Release all locks. All calls allowed.
1 Outgoing STD and ISD calls are blocked.
2 Outgoing STD, ISD, 95, mobile and WLL calls are blocked.
3 Outgoing ISD calls are blocked.
4 All outgoing calls are blocked.
7 Outgoing STD, ISD and 95 calls are blocked.
8 Outgoing STD, ISD, 95 and ISP calls are blocked.
To unlock fully:
As can be seen from the table above, to unblock and allow all outgoing calls, dial: 124-xxxx-0.
For Airtel Centrex (CUG) users:
If you are part of a virtual-CUG service being provided by Airtel, the format changes to:
Set/change secret code: *23*-xxxx-yyyy-#
To lock/unlock: *24*-xxxx-L-# where L is the locking digit in the table above