GSM & USSD Codes Reference

Every GSM code you might need, organized by category. Search by keyword, filter by type, and copy any code with one click.

Call Forwarding

Code	What it does	Example
`*21[number]#`	Activate unconditional forwarding (all calls)	`*21+491701234567#`
`##21#`	Deactivate unconditional forwarding
`*#21#`	Check unconditional forwarding status
`*61[number]**[seconds]#`	Forward when no answer (set ring time in seconds: 5-30)	`*61+491701234567**20#`
`##61#`	Deactivate no-answer forwarding
`*#61#`	Check no-answer forwarding status
`*67[number]#`	Forward when busy	`*67+491701234567#`
`##67#`	Deactivate busy forwarding
`*#67#`	Check busy forwarding status
`*62[number]#`	Forward when unreachable (phone off or no signal)	`*62+491701234567#`
`##62#`	Deactivate unreachable forwarding
`*#62#`	Check unreachable forwarding status
`##002#`	Cancel ALL forwarding rules at once
`##004#`	Cancel all conditional forwarding (no answer + busy + unreachable)

Call Waiting

Code	What it does	Example
`*43#`	Activate call waiting
`#43#`	Deactivate call waiting
`*#43#`	Check call waiting status

Caller ID / CLIR

Code	What it does	Example
`#31#[number]`	Hide your number for the next call only	`#31#+491701234567`
`*31#[number]`	Show your number for the next call (if normally hidden)	`*31#+491701234567`
`*#31#`	Check your caller ID (CLIR) status
`*#30#`	Check incoming caller ID (CLIP) status
`*#76#`	Check connected line presentation (COLP) status
`*#77#`	Check connected line restriction (COLR) status

Call Barring

Code	What it does	Example
`*33[PIN]#`	Bar all outgoing calls Note: PIN is your call barring password (default is often 0000 or 1234, set by carrier)
`##33*[PIN]#`	Remove outgoing call bar
`*#33#`	Check outgoing call bar status
`*331[PIN]#`	Bar all outgoing international calls
`##331*[PIN]#`	Remove international call bar
`*35[PIN]#`	Bar all incoming calls
`##35*[PIN]#`	Remove incoming call bar
`*#35#`	Check incoming call bar status
`*351[PIN]#`	Bar incoming calls when roaming
`##330*[PIN]#`	Remove ALL call barring

Phone & SIM Info

Code	What it does	Example
`*#06#`	Show IMEI number (device identity) Note: Write this down and keep it safe. Needed if your phone is lost or stolen.
`*#07#`	Show SAR (radiation) information Note: Works on most Android phones. Shows the specific absorption rate.

Voicemail

Code	What it does	Example
`*004[number]#`	Set all conditional forwarding to voicemail/number at once Note: Sets no-answer, busy, and unreachable forwarding in one step
`##004#`	Remove all conditional forwarding (clears voicemail forwarding)

Network Selection

Code	What it does	Example
`##4636##`	Phone info and network details (Android only) Note: Opens a hidden Android menu with battery, network, and usage stats
`##7780##`	Factory reset (Android only, use with caution) Note: Resets phone to factory settings. All data will be erased.

Need help setting up call forwarding? Use our interactive setup tool

What are GSM codes?

GSM codes (also called USSD codes or MMI codes) are short dial strings you enter on your phone's keypad to activate, deactivate, or check carrier features. They work on virtually every mobile phone and carrier worldwide, without needing an app or internet connection.

The most common use is call forwarding, but GSM codes also control call waiting, caller ID, call barring, and phone information like your IMEI number.

How to use GSM codes

Open your phone's dialer (the app you use to make calls)
Type the code exactly as shown, including all asterisks (*) and hash symbols (#)
Replace placeholders like [number] with the actual phone number (including country code)
Press the call button
Wait for a confirmation message on screen

Codes starting with ** activate a feature. Codes starting with ## deactivate it. Codes starting with *# check the current status.

Most useful codes at a glance

What you want	Code
Forward calls when you don't answer	`*61[number]**20#`
Cancel all forwarding	`##002#`
Check your IMEI	`*#06#`
Hide your number for one call	`#31#[number]`
Turn on call waiting	`*43#`
Check forwarding status	`*#21#`

For a detailed call forwarding guide

If you're specifically looking to set up call forwarding, our interactive call forwarding tool lets you pick your carrier and generates the exact code with your phone number pre-filled. We also have a step-by-step guide and complete GSM codes reference article with more detail on each code category.

Forward missed calls to an AI assistant

The most practical use of call forwarding codes is routing unanswered calls to a service that actually picks up. Safina is an AI phone assistant that answers when you can't, asks the caller what they need, and sends you a summary. Set it up with the forwarding codes above in about 5 minutes.