Top 10 Most Useful MMI Code You Should Know in 2025

Did you know that your phone can reveal hidden menus, expose if your calls are being secretly forwarded, or even bring a dead-slow phone back to life without installing any application🈸?

All this you can do by just dialing some numbers, letters, and symbols called the MMI code. With the correct MMI code, you can check your IMEI number, call forwarding details, and also update your device.

So, what exactly is the MMI code 🤔?

In this blog📃, we will discuss the 10 most useful MMI codes you should know in 2025.

So, let’s get into it🚀

What is the MMI code?

MMI code stands for Man-Machine Interface code. It is a special set of letters and symbols you put into your cell phone. This code can change the device settings, manage call forwarding, display SIM card information, or enable any functions.

So, the MMI code should be used carefully and knowing what it can do.

MMI code is a combination of numbers, asterisks (*), and hashtags (#) that you dial to interact with your mobile network.

Not all codes with asterisks and hashtags work on your device. Some depend on your mobile carrier and device, also. If you enter a code that doesn’t work, you will receive an error message of “Invalid MMI code” or “connection problem.”

You can also use some MMI code to use the hidden testing menu to check your phone’s hardware and software.

Whether you want to fix a connection problem, manage call forwarding, or check your SIM card status, MMI codes can help you.

However, you should always use them with care.

Some codes only show information, but others can reset your phone or change settings permanently.
Make sure that you research the code before using it.

10 most useful MMI codes in 2025

There are a lot of MMI codes that are in use at present. Each of them has different functions and functions differently. Some MMI code helps you to extract SIM card information, whereas some MMI code helps to change and manage device settings.

Here are some of the most useful MMI codes that you can use in 2025.

1. *#06# : Display IMEI number

This MMI code reveals the IMEI (International Mobile Equipment Identity) number of your mobile device.

The IMEI number is a unique ID that is used by your network operator to identify your phone and is useful when you need to report a lost phone, unlock your device, or register your SIM card. It works on nearly every phone and with all mobile networks.

This MMI code is simple to use. Just open your dialer and type the code; it does not require a browser, a web application, or a setting. This is one of the widely used and supported MMI codes in the world, and it is instant. Also, you don’t need your internet or your network provider’s support.

2. *#*#4636#*#*: Access phone testing menu (battery, usage, network info)

This useful MMI code opens the testing menu on many Android phones. It provides information about your battery, app usage, signal strength, and mobile network connection, and allows the user to check the real-time network info, as well as the ability to ping the network. It is especially useful for troubleshooting connection problems and checking that the mobile device is properly connected to the network operator.

Often, only users with technical knowledge, as well as support staff, would use this menu to work through problems, and do so without third-party apps. Furthermore, it simply gives information and does not make any alterations. However, it does allow you to see detailed information about both the function of your mobile device and how it is interacting with the mobile network.

3. *#21# : Check call forwarding status

This MMI code lets you know whether your calls, messages, or data are being diverted to another number. It checks whether your mobile phone has call forwarding features currently activated. This feature is useful if you suspect someone may have redirected your calls without your consent or knowledge.

This MMI code can inform you if your network provider turned on call forwarding as a default setting. When you dial the code, it will show you on the phone whether call forwarding is engaged for voice, data, or SMS.

This code allows you to keep your phone’s privacy and call management in control. This code can be used on many devices, depending on your mobile network and the network you are using.

4. *#67# : Check call forwarding when busy

This MMI code simply indicates the destination of a call when your number is busy or you have rejected the call. It is usually used to confirm whether your calls have been forwarded to voicemail or another number.

It can help keep you aware of important calls, even while already connected to another line. If you are using services provided by a network provider, this code will confirm their call default handling. This is also useful for business users, who use two numbers, or for forwarding calls while in meetings.

If you are experiencing connectivity issues or receiving missed calls reports, this code can help identify where the calls are currently routed.

5. *#0*#: Run full hardware test (works on many Android devices)

This MMI code is like an inbuilt diagnostic tool for your phone. It runs a full test of the hardware for many Android devices, especially Samsung. When you enter this code, your mobile device shows options for testing the screen, camera, speakers, sensors, and more.

This can be helpful if something is not working correctly on your phone or if you want to check your phone’s health. It opens the hidden testing menu of your mobile phone, which is likely used by hardware repair people and advanced users.

It can be helpful for hardware testing, but doesn’t change any settings – just provides a quick way to identify whether the hardware is failing without needing a third-party testing app.

6. *31#: Hide caller ID for outgoing calls

This simple MMI code lets you hide your phone number when making a call – instead of your number being displayed on the phones of the person receiving the call, they will see “Private Number” or “Unknown”.

This is helpful if you wish to keep your personal number private or if you are calling a person whom you do not want to see your calling number. The code can be activated on most mobile phones today, and generally is supported by all network providers.

To unhide your number, just type #31#. This is a quick way to manage your caller ID settings on your mobile network, such as if you are a business user, calling private if you will. While the ID masking process via an MMI code works for outgoing calls or messages, it does not affect incoming calls or text messages.

7. *#62#: Check call forwarding when unreachable

This MMI code will check where your calls go when your phone is disconnected or out of reach of the service area, or out of service altogether. It’s very useful for identifying call forwarding settings that you are not aware of.

If your network provider is forwarding your calls to voicemail or a different number whenever your phone is unreachable, this MMI code will show you. This MMI code is super valuable for people who are traveling or have unreliable signals.

This tool will give you more confidence by showing you what was supposed to happen with your mobile device whenever it was unable to accept calls, especially in poor mobile network locations or while roaming.

8. *#*#7780#*#*: Perform a factory reset (soft reset)

This MMI code resets your phone back to factory settings. It will erase all apps, accounts, and data, leaving the operating system alone. This is referred to as a ‘soft’ reset, and is intended to fix software problems, malware removal, or prior to the resale of a device.

This code should be used with caution, as it cannot be undone. Make sure you back up any data first. The code only works on Android phones, and not all network providers allow this command. If your mobile device has been slow or is experiencing connection problems, this reset may give it a fresh start without having to delete the operating system.

9. *#*#232338#*#*: Show Wi-Fi MAC address

This MMI code displays the Wi-Fi MAC (Media Access Control) address of your phone. Each device has a unique ID, so it will be used to connect to Wi-Fi networks. You may need this if and when you set up a secure Wi-Fi router for the first time or if your organization or school restricts access to their network.

Sometimes, network operators or local colleges and universities, and systems administrators will ask for this code. It will be useful if you have problems using Wi-Fi on your mobile device.

Keep in mind that this code does not change any settings on your device and simply displays your MAC address so that you can copy it or fill it in for you during network setup. It should work on any Android phone connected to a mobile network.

10. *#*#1472365#*#*: Test GPS functionality

This MMI code runs a GPS test on your phone to evaluate its connection to the GPS satellites and to see the location data you have received. This code is tremendous if your maps or location-based apps are not working correctly.

If you are getting wrong directions or a delayed GPS signal, this will test and provide you with more information on the issue. The MMI code can mainly be used by travelers and delivery drivers, or anyone who depends on their mobile device’s GPS for accuracy. Tips when using the MMI code

Tips when using the MMI code

MMI codes are useful tools that can help you unlock hidden features by directly communicating with your mobile network. It is important to know what the MMI code can do before dialing. Each code has a different function and acts differently.

Here are some tips when using the MMI code:

• Know what the MMI code does before using it: Always understand what the MMI code does. Some change settings, others check network operator info, or reset your mobile device. Using the wrong code can cause issues.

• Use only trusted and verified codes: Only use MMI codes from trusted sources or your network provider. Unverified codes may cause errors or change your mobile network settings unexpectedly.

• Check compatibility with your device and network provider: Not all codes work on all phones. Some depend on your mobile device or network operator. Unsupported codes often return “Invalid MMI code” or “connection problem.”

• Restart your phone if you get an “Invalid MMI code” error: If you see an “invalid MMI” message, restart your phone or toggle airplane mode. This refreshes the mobile network connection and may fix the issue.

• Avoid using reset codes without backing up data: Factory reset codes erase data from your mobile device. Always back up important files before using them. These codes affect your man-machine interface settings.

• Use MMI codes in areas with good signal strength: A strong mobile network signal helps MMI codes work properly. Weak signal areas may cause failure or errors when contacting your network provider.

• Contact your network operator if issues continue or codes fail: If codes don’t work, ask your network provider for help. They can confirm if the code is valid or fix connection problems on your mobile network.

Conclusion

MMI codes are powerful tools that can help you check your phone settings, show important information, and fix software issues just by dialing codes. You can change your phone settings, fix issues related to software, and check SIM or device info.

However, it is important to understand and know how the MMI code works on different devices and networks. Some carriers can support the MMI code, whereas some may not support the same code.

Also, dialing the wrong MMI code can change unwanted device settings, which can be a serious issue if you don’t know how to change them.

So, always be careful before dialing any MMI code. Understand its purpose and what it can do to your device. With the correct MMI code, you can control your device better and resolve issues faster.

FAQs

What happens if I dial the wrong MMI code?

If you dial an invalid or unsupported MMI code, you’ll usually get an error message like “Invalid MMI Code” or “Connection problem.” It won’t damage your phone, but some codes that change settings or reset your phone should be used with caution.

Do MMI codes work on all phones?

Not always. Some codes only work on Android, while others may not work on certain phone models or with specific network providers.

Can I use MMI codes without an internet connection?

Yes. Most MMI codes do not need the internet. They work through your phone’s connection to the mobile network.

Do I need to install an app to use MMI codes?

No, just open your phone’s dialer, enter the code, and press the call button. It’s quick and doesn’t require any app.

Is there a risk of losing data with MMI codes?

Only if you use reset codes like ##7780## or other factory reset codes, these can erase data, so back up your files first.

Can MMI codes help fix network issues?

Yes. Some codes help you check network strength, SIM status, or test your phone’s hardware to find and fix connection problems.