Did you know that your iPhone / Android smartphone has a ton of secret hidden menus that you can only access by dialing special codes? I’ve included a short list here of some of the most useful hidden menus. Most of the ones I have listed are for the iPhone since the secret Android phone menus vary widely depending on the model and manufacturer. For more Android ones you will have to do a web search based on what phone you have.
*#06# – Displays IMEI
*3001#12345#* + “Call” – Accesses a hidden Field Test menu
*#43# + “Call” – Displays call waiting status
*43# + “Call” – Enables call waiting
#43# + “Call” – Disables call waiting
*#21# – Displays call forwarding status
##002# + “Call” – Disables all call forwarding
*33*pin# – Enables call barring
#33*pin# – Disables call barring
#31#phone-number + “Call” – Blocks caller ID for the current phone call
*3370# + “Call” – Enables “Enhanced Full Rate” and improves voice quality on GSM networks (may impact battery life)
*#5005*7672# + “Call” – Displays your carrier’s message center phone number
(The first code will work on most Android phones and the second one will work on all Android phones)
*#*#4636#*#* – Accesses a hidden test menu with sections for network, battery information and usage stats.
Under the “About phone” option in Settings, tap “Build number” seven times – this will enable a new “Developer options” menu in Settings that gives you access to a treasure trove of functions.