USSD short codes are handy for setting up diverts on your mobile phone to control how this works regardless of the handset type and the menus options.

This feature  has been available since the first GSM networks were launched and the phone menu doesn’t do anything different than sending these codes. However, this gives you a faster access to your settings and in addition it offers you one feature which isn’t available through most mobile phone menus (defining after which time a call should be forwarded if you don’t reply). Please remember that this information is stored on the GSM network, not on your GSM device. So doesn’t matter if you change your SIM card to another terminal, the settings are stored as long as you don’t change it.
USSD codes works in the same way on all networks and GSM phones, you enter the codes as though you are dialiing a number and a response will flash to the screen.

USSD_Code = the feature code the mobile phone should send to the network
@ = Send (green) phone button

Configuring Call Diverts

Divert all Calls (21)

All your incoming calls will be forwarded, doesn’t matter if your phone is switched on or not. The USSD
code is “21”.

Forwarding: **21*DESTINATION_NUMBER# @

Activate: *21# @
Deactivate: #21# @
Delete: ##21# @
Check Status: *#21# @

Divert if no Reply (61)

All the incoming calls will be forwarded if not taken within a defined time. The USSD code is “61”.
Forwarding: **61*DESTINATION_NUMBER# @

Activate: *61# @
Deactivate: #61# @
Delete: ##61# @
Check Status: *#61# @

In addition you can tell the network after which time the call should be diverted. Here the GSM specifications
define a time between 5 to 30 seconds:

Forwarding: **61*DESTINATION_NUMBER*DELAY# @
The DELAY time can be 5, 10, 15, 20, 25 or 30 seconds.

Divert if Unavailable (62)

All the incoming calls will be forwarded if the phone is switched off or out of network coverage. The USSD
code is “62”.

Forwarding: **62*DESTINATION_NUMBER# @

Activate: *62# @
Deactivate: #62# @
Delete: ##62# @
Check Status: *#62# @

Divert if Busy (67)

All the incoming calls will be forwarded if another call is in progress. The USSD code is “67”.

Forwarding: **67*DESTINATION_NUMBER# @

Activate: *67# @
Deactivate: #67# @
Delete: ##67# @
Check Status: *#67# @

All Conditional Diverts (004)

You can also activate, switch on/off, check or delete all conditional forwards (61, 62 and 67) with just
one USSD code. The USSD code is “004”.

Forwarding: **004*DESTINATION_NUMBER# @

Activate: *004# @
Deactivate: #004# @
Delete: ##004# @
Check Status: *#004# @

Deactivate all Diverts (002)

This USSD code deactivates all call forwardings with one single command. The USSD code is “002”

##002# @

Please note that using the unconditional “Divert all Calls (21)” overwrites all conditional call forwarding!