Invalid MMI Code? Here Are the Causes and How to Fix It

Article Summary

Main problems: weak signal or unstable network make a request MMI code fail.
Check the writing; typos in numbers, stars, or hashes as well code which is not appropriate operator often the cause.
Quick solution: double check MMI code, activate airplane mode, add a comma, or restart MOBILE PHONE.
If still having problems, delete it. cache Phone app, temporarily disable one of them driver's license, or update OS.

Invalid MMI Code? Here Are the Causes and How to Fix It

You're trying to check your remaining credit or buy a data plan, but instead you get a confusing error message on your phone screen. This invalid MMI code message often appears out of the blue without any prior warning.

Incidents like this disrupt what were once simple activities, especially if you're in a hurry to get your internet data. However, this problem isn't as serious as you might think and can be easily resolved on your own.

Before panicking and rushing to the counter, it's best to first understand the root of the problem so you can find a more targeted solution. Here's an explanation of invalid MMI codes, from their definition to how to fix them.

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What is MMI Code?

MMI stands for Man Machine Interface, a series of numbers and symbols used to access certain services through a phone app. This code allows users to check their balance, check their data quota, activate packages, and even transfer credit without needing to open an additional app.

It works similarly to a dedicated communication channel between the phone and the mobile operator's server. Once the code is typed and the call button is pressed, the system sends the request via the USSD network to the operator's data center.

If the transmission process goes smoothly, the results will appear immediately on the screen with the requested information. However, if there's a problem along the way, an invalid MMI code notification will appear, which can be confusing for many.

Cause of Invalid MMI Code

Before rushing to find a solution, it's a good idea to first identify some of the factors that commonly trigger this problem. Here are some common reasons why MMI codes can suddenly become invalid.

Weak signal or unstable network: MMI codes are highly dependent on cellular connection, so if the signal is lost or you frequently switch networks, the request will not reach the operator's server;
Coding error: Just one typo, whether a wrong number or an asterisk or hash symbol, can immediately cause the operator's system to reject the request;
The code is no longer valid: Operators sometimes update or delete old codes, so a code that worked before may not work now;
Code does not match operator: Each provider has its own MMI code, so the code Telkomsel for example, it won't work if you try it on an Indosat or XL card;
Phone app crash: A buildup of cache or a small bug in the dialer app can disrupt the MMI code sending process;
Dual SIM setup problem: If your phone uses two cards at once, sometimes the system will choose the wrong SIM path to send the MMI code, causing the request to fail to be processed.

How to Fix Invalid MMI Code

Double check your code. Retype it. MMI code Carefully, make sure there are no mistyped numbers or symbols before pressing the call button.

Check code compatibility with operator: Make sure the code you use matches the card provider currently installed on your cellphone;
Make sure the signal is stable: Move to a location with a stronger network or wait a while before trying to send the MMI code again;
Turn airplane mode on and off. This simple trick helps refresh a network connection that has been stuck for no apparent reason;
Add a comma at the end of the code: This method gives the system additional time to process the code before it is finally sent to the operator's server;
Clear phone app cache: Go to the Settings app menu, find the Phone or Dialer app, then clear the cache that may have accumulated and interfered with performance.
Temporarily disable one of the SIM cards: If you are using a dual SIM phone, try turning off one of the slots first so the system doesn't get confused about which code delivery route to choose;
Restart your phone: Restarting the device can help clear out minor bugs as well as refresh problematic network connections;
Update HP operating system: Make sure your phone is using the latest software version because old bugs are sometimes fixed through official system updates.

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That concludes our discussion of the causes of invalid MMI codes. First, identify the cause, then try the solutions outlined above. We hope this is helpful.

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