Some common iPhone secret codes include:

  • ##001127#: Resets your iPhone's network settings.
  • ##872563#*: Resets your iPhone's diagnostic mode.
  • *3001#: Opens the Field Test menu.
  • 500561412#: Opens the Cellular Data Usage menu.
  • *#55#: Opens the SIM Card Lock menu.
  • *337#: Displays your iPhone's IMEI number.
  • *#4377#: Enters your iPhone into Service Mode.
  • *#9999#: Opens the Emergency Calls menu.