Universal (all GSM phones) Secret Codes & USSD Dial Codes (2026)
Universal (all GSM phones) secret codes are short USSD and MMI sequences typed directly into the phone dialer that open diagnostic screens, service menus and network information panels normally hidden from the standard settings app. They let you inspect the hardware and firmware of your Universal (all GSM phones) device without installing anything.
Typical uses include checking the exact firmware build, reading battery voltage and health data, running display and touch tests, viewing the serving cell and signal strength, and displaying the IMEI. Each entry in the table below is documented publicly and labelled with a risk level so you know what will happen before you dial.
Codes execute immediately on most Android builds, with no confirmation dialog, so read the risk column carefully. Anything marked destructive erases user data the moment it is accepted by the dialer, and there is no way to cancel or undo it afterwards.
Full Universal (all GSM phones) secret code list (11 codes)
Every code below is documented from public device and service documentation. None of these codes erase user data, but always read the risk column first.
| Code | What it does | Category | Risk level |
|---|---|---|---|
| Show IMEI. Displays the device IMEI / serial number. Works on virtually every mobile phone. | info | Safe — read only | |
| Call Forwarding Status. Shows whether all-call forwarding is active and to which number. | network | Safe — read only | |
| Forwarding When Unanswered. Shows the number that receives calls you don't answer. | network | Safe — read only | |
| Forwarding When Unreachable. Shows where calls go when your phone is off or has no signal. | network | Safe — read only | |
| Forwarding When Busy. Shows the number that receives calls while you're on another call. | network | Safe — read only | |
| Cancel All Forwarding. Turns off every type of call forwarding on the line. | network | Caution — changes settings | |
| Caller ID Status. Shows whether your number is hidden or shown on outgoing calls. | network | Safe — read only | |
| Call Waiting Status. Shows whether call waiting is currently enabled. | network | Safe — read only | |
| Call Barring Status. Shows whether outgoing/incoming call barring is switched on. | network | Safe — read only | |
| Enable Call Waiting. Turns on call waiting so a second caller can reach you mid-call. | network | Caution — changes settings | |
| Disable Call Waiting. Turns off call waiting. | network | Caution — changes settings |
How to use Universal (all GSM phones) codes
- Open the Universal (all GSM phones) dialer and go to the keypad, exactly as if you were dialling a number.
- Type the code precisely as shown, including the leading
*and the trailing#. Autocorrect and paste can drop characters, so type it out. - Most sequences fire the moment the final character is entered — you usually do not press call.
- If the screen does not change, press the call button once; a few USSD strings need it.
- Back up photos, messages and app data before running anything marked destructive, then confirm you are on the right device.
- Nothing at all happening usually means the code is disabled on your firmware or blocked by your carrier — it is not a fault with your handset.
Universal (all GSM phones) secret codes — FAQ
Do all Universal (all GSM phones) phones support the same secret codes?
No. Code support depends on the model, the firmware version and in many cases the carrier that supplied the handset. Older Universal (all GSM phones) models often expose more service menus than the newest releases, because manufacturers gradually lock engineering tools behind signed diagnostic apps. If a code does nothing, it has almost certainly been removed or disabled on your build rather than typed incorrectly.
Is it safe to dial Universal (all GSM phones) secret codes?
The codes we mark as "safe" only display information or open a read-only test menu, so they cannot damage your phone. Codes marked "caution" change a setting or start a hardware routine you should understand first, and codes marked "destructive" erase user data instantly with no confirmation dialog. Always back up before running anything in the destructive category.
Why does nothing happen when I enter a code?
Three common reasons: the code is not supported on your firmware, your network operator has blocked the USSD string, or the dialer requires you to press the call button for that particular sequence. Try the code on a different SIM or in airplane mode, and confirm every character including the leading asterisk and trailing hash.
Will using these codes void my Universal (all GSM phones) warranty?
Simply reading diagnostic information does not void a warranty. However, changing radio band settings, running write operations in an engineering menu, or performing a factory format can leave your device in a state a service centre may treat as user-caused. Stick to read-only codes unless you are following official repair guidance.
Can these codes unlock a network-locked Universal (all GSM phones) phone?
No. Network unlocking requires a carrier-issued unlock code or an official unlock request through your operator. Any site promising a free universal unlock dial code is misleading you. The codes listed here only expose diagnostics, network status, firmware information and factory reset routines.
How do I find my IMEI on a Universal (all GSM phones) device?
Dial *#06# on any GSM or LTE phone, including every Universal (all GSM phones) model, and the IMEI appears immediately. You can also validate the number with our IMEI checker, which runs the Luhn checksum used by the GSMA to detect mistyped or invented IMEI numbers.