Are these codes safe to use?

Use at your own risk. We list only codes documented by vendors or standards, but results may vary by model/region.

Do the same codes work on every phone?

No. Some are global GSM-MMI codes, others are vendor/carrier-specific and may be disabled by firmware.

Where do the codes come from?

From official specs (3GPP), Apple/Samsung/Google documentation, and Swiss carriers (Swisscom, Sunrise, Salt).

Will using codes void my warranty?

Diagnostic codes normally do not, but anything that changes settings could. When in doubt, do not proceed.

Service Functions and Secret Codes (mobile phones)

Use at your own risk. The codes listed here come from official specifications and vendor/carrier documentation where available. Device‑specific service codes may vary by model or region. Any changes or damage caused by misuse are solely the user’s responsibility.

This page curates service functions and secret codes for mobile phones. Many are global (GSM/MMI); others are vendor‑ or carrier‑specific.

Phone - engineering menus and tests

Depending on the device, there may be manufacturer-specific test and service menus. The sequences below work on many Android devices; use with care.

GSM/MMI control codes - general functions

Standardised MMI/USSD control per 3GPP TS 22.030; applies in EU/CH/US/FR (carrier‑dependent).

Code Function Note

*#0*# General test menu (display, sensors, audio)

*#2663# Show TSP/Wi‑Fi firmware versions, update TSP/Wacom/Wi‑Fi Not officially documented; may reboot device

*#9900# System dump / clear logs (free up storage) Use log cleanup only

*#12580*369# SW/HW info (PDA/CP, manufacturing date)

*2767*3855# Full factory reset (erases all data) Data‑loss risk

*#06# Show IMEI (Apple officially documents Settings > General > About) Official guide: Apple Support

##002# Erase all call forwardings (GSM standard) See 3GPP TS 22.030 (MMI): ETSI/3GPP

*#21# Interrogate status of all call forwardings (GSM standard) 3GPP TS 22.030 (CFU/CFB/CFNR/CFNRY SC 21/67/61/62): ETSI/3GPP

*43# / #43# Call Waiting on/off (GSM standard) Service code 43 per 3GPP TS 22.030: ETSI/3GPP

Sunrise: *121# Check prepaid balance (official) Sunrise Support

Salt: #121# + Anruf Show PrePay balance (official) Salt Help

Swisscom: SMS 'STATUS' an 444 Prepaid balance/allowance via SMS or Cockpit Swisscom Help (444) · Cockpit

Code	Function	Note
`#0#`	General test menu (display, sensors, audio)
`*#2663#`	Show TSP/Wi‑Fi firmware versions, update TSP/Wacom/Wi‑Fi	Not officially documented; may reboot device
`*#9900#`	System dump / clear logs (free up storage)	Use log cleanup only
`#12580369#`	SW/HW info (PDA/CP, manufacturing date)
`27673855#`	Full factory reset (erases all data)	Data‑loss risk
`*#06#`	Show IMEI (Apple officially documents Settings > General > About)	Official guide: Apple Support
`##002#`	Erase all call forwardings (GSM standard)	See 3GPP TS 22.030 (MMI): ETSI/3GPP
`*#21#`	Interrogate status of all call forwardings (GSM standard)	3GPP TS 22.030 (CFU/CFB/CFNR/CFNRY SC 21/67/61/62): ETSI/3GPP
`*43# / #43#`	Call Waiting on/off (GSM standard)	Service code 43 per 3GPP TS 22.030: ETSI/3GPP
`Sunrise: *121#`	Check prepaid balance (official)	Sunrise Support
`Salt: #121# + Anruf`	Show PrePay balance (official)	Salt Help
`Swisscom: SMS 'STATUS' an 444`	Prepaid balance/allowance via SMS or Cockpit	Swisscom Help (444) · Cockpit

Official references

Note: You use any codes at your own risk.