MMI code stands for Man-Machine Interface code. It is a code you dial on a mobile phone to access network or device functions, such as checking your IMEI, balance, or service settings.

Quick Scoop

MMI codes usually look like a mix of * and # symbols plus numbers, for example *#06#. They are often used as shortcuts for phone or carrier features without needing the internet.

Common uses

  • Check IMEI number: *#06#.
  • Check balance or data usage: carrier-specific codes like *199# may be used by some networks.
  • Access device or network info: some codes open diagnostic or service screens.

Invalid MMI code

If you see “connection problem or invalid MMI code,” it usually means the phone could not process the code properly, often because of a network, SIM, or formatting issue. A common example is entering a code that your carrier or device does not support.

In one line

MMI code = a special phone code used to quickly access mobile network or device functions.

TL;DR: MMI codes are short dialer codes for phone and network tasks, and *#06# is the most common example for checking IMEI.