The GSM standard allows most of the functions to be controlled by entering codes into the keypad of a mobile phone: you can set diverts and the like, accept or reject calls, or even change your PIN code by typing at the keypad.
Unfortunately, not all the codes listed here are enabled by every network. If a code isn't supported, it simply won't work: you won't break anything by trying to use it!
Many (though not all) handsets offer menus to do most of these things, but they vary from handset model to model, and are sometimes hidden by networks who don't want to confuse their users.
If you can use the codes directly, you can also store them in memory, so that you can easily recall and reuse them. For example, you might want to divert all calls to your office phone on a regular basis: from memory, it's just two or three keypresses to set up or cancel such a diversion.
You know about voice calls, but there are also fax calls, data calls, ALS (line two) calls and SMS messages. Calls of different types can all have different settings associated, using the relevant "bearer code" as shown in the examples below.
Some networks don't support all services, so some GSM codes will fail. Others sometimes seem to use their own interpretation of the GSM codes.
If you are having trouble setting call diversion, try ##002#[SEND] and/or ##004#[SEND] to clear all existing diverts first. You probably have to cancel a 'no reply' diversion before you can set another with a different timeout.
Call Divert (all call types)All Divert Voice CallsAll Divert Data CallsAll Divert Fax CallsAll Divert Line 2 CallsAll |
You use call barring to control what calls can be made or received by your account.
The barring code is specific to the network. Ask your service provider.
Note that Call Barring can't work if call diverts are active, even the autodivert set by the network.
All calls
Set: **330*barring code#[SEND]
Cancel: ##330*barring code#[SEND]
Query: *#330#[SEND]
Outgoing calls
Set: **333*barring code#[SEND]
Cancel: ##333*barring code#[SEND]
Query: *#333#[SEND]
Incoming calls
Set: **35*barring code#[SEND]
Cancel: ##35*barring code#[SEND]
Query: *#35#[SEND]
Outgoing international calls
Set: **331*barring code#[SEND]
Cancel: ##331*barring code#[SEND]
Query: *#331#[SEND]
Outgoing international calls except to home country
Set: **332*barring code#[SEND]
Cancel: ##332*barring code#[SEND]
Query: *#332#[SEND]
Incoming calls when outside home country
Set: *351*barring code#[SEND]
Cancel: #351*barring code#[SEND]
Query: *#351#[SEND]
Cancel All Call Barring
#330*barring code#[SEND]
There is no provision in the GSM specification for diverting SMS messages
Bar incoming SMS messages
Set: *35*barring code*16#[SEND]
Cancel: #35*barring code*16#[SEND]
Set: *43#[SEND]
Cancel: #43#[SEND]
Query: *#43#[SEND]
Reject: 0 [SEND]
Drop current call and answer: 1 [SEND]
Hold current call and answer: 2 [SEND]
Outgoing CLI Release (recipient sees your number)
Release: *31# destination [SEND]
Withhold: #31# destination [SEND]
Query default: *#31#[SEND]
Incoming CLI Presentation (you see the caller's number)
Allow: *30#[SEND]
Prevent: #30#[SEND]
Query default: *#30#[SEND]
Where nnn is the memory location number
nnn#[SEND]
Change Call Barring pin code
**03*oldpin*newpin*newpin#
Change SIM pin code
**04*oldpin*newpin*newpin#
Change SIM pin2 code
**042*oldpin*newpin*newpin#
Unblock SIM pin code
**05*PUK*newpin*newpin#
Unblock SIM pin code
**06*PUK2*newpin*newpin#