Users of Xiaomi and Redmi smartphones often have to temporarily or completely disable one of the devices. SIM-This may be because you want to save battery power, avoid unnecessary calls outside of working hours, or switch to using only Wi-Fi. MIUI This process is implemented quite flexibly, allowing you to manage SIM cards without physically removing the tray.
But beyond just a simple switch in the settings, there are more complex scenarios that require a deep understanding of how the device works, such as if you plan to sell a phone, not only do you have to take out the Symbol, but you also have to unplug the Mi Cloud account, which is often linked to the phone number, and ignoring this step can lead to the device being locked by a new owner.
In this article, we will take a look at all aspects of SIM card management in detail, from the banal on and off menus to fully unlocking a device from a carrier. Attention: some actions related to unlocking a bootloader or changing the region may affect the warranty, so approach them consciously.
Basic management SIM-mapping MIUI
The easiest and safest way to deactivate a SIM card is to use the built-in operating system interface, which does not require root rights or make changes to system files. To begin, open the Settings app on your Xiaomi or Redmi smartphone.
In the settings menu, find the section SIM-This shows all the cards that are installed in the device. If you have a dual-slot model, you'll see two separate switches. To turn off a particular card, just turn the slider to the "Off" position".
After disabling the network icon at the top of the screen will disappear for the selected slot, and instead it may appear crossed out SIM-This means that the communications module stopped scanning the operator's network, but the physical card remained in the phone. You can turn it back on at any time, returning the slider to its original position.
☑️ Pre-switch check
It's worth noting that when you turn off one of the cards in dual SIM mode, the second one continues to work normally, you can still receive calls and use mobile Internet if it is configured on an active card, and the MIUI system automatically redirects calls to the active number.
Disable notifications and subscriptions Mi Cloud
Often, the phrase “disable SIM card” means users want to get rid of intrusive notifications about Xiaomi services or subscriptions tied to a number. In some regions, when activating the phone, you automatically make trial subscriptions to services like Mi Video or Mi Music.
To stop writing off, it is not enough to simply remove the SIM card. You need to go to your account settings. Go to Settings → Mi Account. If you see active subscriptions, they must be canceled manually through the GetApps app store interface or on the official Mi Account website.
⚠️ Note: Simply removing a number from your phone settings does not cancel paid subscriptions for the operator or Google services.
It is also important to untie the number from the Find Device function. If you are selling a phone, go to Find the device and click "Exit." If you do not do this, the phone will be locked after resetting, since Xiaomi's security system requires you to enter a password from the account to which the number is associated.
Why are SMSes coming from Xiaomi?
To completely clear the SIM card data from the system before selling, reset the network settings. Go to Settings → Connections and Sharing → Reset Wi-Fi, mobile networks and Bluetooth. This will remove all saved APN hotspots and settings associated with your carrier.
Physical extraction and tray work
If the software shutdown is not required, but it is necessary to physically remove the card, you will need a special key-clip, which comes with Redmi. SIM-cards are usually located on the lower or lateral end of the device.
Put the paper clip in the hole next to the tray and press until you click. The tray will extend. Carefully remove it, trying not to damage the contacts of the card itself or the spring mechanism of the phone. On some Xiaomi models, the tray is combined: on one side of the SIM, on the other, a microSD card.
| Type of tray | Slot 1 | Slot 2 | Features |
|---|---|---|---|
| Hybrid | Nano-SIM | Nano-SIM / microSD | You can’t use 2 SIMs at the same time. |
| Separate | Nano-SIM | Nano-SIM | The memory card is inserted separately or in a special slot |
| Triple. | Nano-SIM | Nano-SIM + microSD | This is a rare option that allows you to use all 3 elements at once. |
After removing the SIM card, the phone will automatically detect the configuration change"SIM-If you insert the card back, the system will ask you to enter the card. PIN-code, if it has been previously installed.
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If the tray is stuck, don't use excessive force. Try gently wiggling the phone or tapping the end slightly to make the mechanism move. Use of glue to extract the tray is strictly prohibited.
Unlocking the network and changing the region
Sometimes users want to “disable” the phone’s link to a specific carrier, especially if the device was purchased abroad or from dealers.
For global versions of Xiaomi, this problem is rare, but it is possible to block by region"SIM-The card is locked or requires an unlock code, which means the device is connected to the network. NCK (Network Control Key).
You can get this code from the official seller or in service centers by providing proof of purchase. Self-unblocking through third-party services can lead to blocking IMEI, after which the phone will turn into a tablet without the possibility of calls.
⚠️ Note: Using software patches to unlock the network on new versions MIUI It often causes the communication module to fail.
There is also the concept of “regional locking.” Some Chinese versions of Redmi may block European frequencies or require region confirmation on first activation, bypassing this limitation usually involves flashing the device to a global version of the software.
Setting priorities and mobile internet
When two SIM cards are installed on a phone, it is critical to set priorities correctly. MIUI allows you to flexibly manage which card is used for calls and which is used for data transfer.
Go to the menu. SIM-You'll find "Mobile Internet" here, select a card that has unlimited traffic or the most favorable terms, and a mistake in choosing will lead to a rapid consumption of the main balance.
Separately, you can set up the default call option, you can choose one card for all outgoing calls, or you can leave the Always Ask setting, which is convenient if you use one SIM card for work and the other for personal contacts.
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Properly setting mobile internet priority saves money, and make sure that the data transfer card is unlimited, not the main voice card.
You can also set the traffic limits for each SIM card separately, and in the Traffic section, set the limits so that the system automatically shuts down mobile internet when it reaches the threshold, preventing unexpected charges.
Solution: SIM is not detected or disabled
There are situations when the user wants to disable the SIM card software, but the phone constantly "disables" it, giving an error "No SIM" or "Only emergency calls" This can be a sign of a hardware malfunction or software failure.
The first thing to do is to clean the SIM card contacts. Fat spots and copper oxidation often cause loss of contact. Wipe the chip with a soft cloth soaked in alcohol. Also check if the card sits tightly in the tray; if it hangs, use an adapter or gently place a piece of paper (without pasting the contacts!).
If the problem is not solved, try resetting your network settings. Go to Settings → Advanced Settings → Recover and Reset → Reset your Wi-Fi, mobile Internet and Bluetooth settings. This action will return your network settings to factory values.
⚠️ Attention: Resetting your network settings will remove all saved Wi-Fi passwords and associated Bluetooth devices.
In rare cases, the problem lies in the slot itself, and if you tap the back lightly, the phone can see it, it can't see the SIM card, and it's probably a contact that's loosened inside the device, and then only repairs at the service center will help.