GSM & USSD Codes

GSM is a cellular communication standard. USSD is a live text-based session with a carrier; codes normally begin with * and end with #. Carrier support and dialing formats vary.

Call forwarding

Code	Function
**21*(number)#	Activate unconditional forwarding
##21#	Deactivate unconditional forwarding
*#21#	Check unconditional forwarding status
**61*(number)**(seconds)#	Forward when no answer
##61#	Deactivate no-answer forwarding
*#61#	Check no-answer forwarding status
**67*(number)#	Forward when busy
##67#	Deactivate busy forwarding
*#67#	Check busy forwarding status
**62*(number)#	Forward when unreachable
##62#	Deactivate unreachable forwarding
*#62#	Check unreachable forwarding status
##002#	Cancel all forwarding rules
##004#	Cancel all conditional forwarding

Call waiting and caller ID

Code	Function
*43#	Activate call waiting
#43#	Deactivate call waiting
*#43#	Check call-waiting status
#31#(number)	Hide number for the next call
*31#(number)	Show number for the next call
*#31#	Check caller-ID restriction status
*#30#	Check incoming caller-ID status
*#76#	Check connected-line presentation status
*#77#	Check connected-line restriction status

Call barring

Code	Function
**33*(PIN)#	Bar all outgoing calls
##33*(PIN)#	Remove outgoing-call barring
*#33#	Check outgoing-call barring status
**331*(PIN)#	Bar all outgoing international calls
##331*(PIN)#	Remove international-call barring
**35*(PIN)#	Bar all incoming calls
##35*(PIN)#	Remove incoming-call barring
*#35#	Check incoming-call barring status
**351*(PIN)#	Bar incoming calls while roaming
##330*(PIN)#	Remove all call barring

Phone and network information

Code	Function
*#06#	Show IMEI number
*#07#	Show SAR information
*#*#4636#*#*	Android phone and network information

Voicemail

Code	Function
**004*(number)#	Set all conditional forwarding to a number
##004#	Remove all conditional forwarding

Do not use codes that reset user data or alter call-barring settings without the owner’s authorization and carrier confirmation.