In modern smartphones brand Xiaomi management of communication modules brought to the software level, which allows you to flexibly configure the operation of the device without physical intervention. SIM-So you can do this quickly, without using a paper clip to extract the tray, to avoid unnecessary roaming costs or to reduce background network activity.
The procedure takes only a few seconds and is performed through the standard settings menu of the MIUI or HyperOS operating system. This is especially convenient if you are in the zone of a bad signal or in a place where you urgently need to stop incoming calls to a specific number.
In this article, we will discuss in detail the algorithm of actions to disable the SIM card on various models of smartphones Redmi and POCO. You will learn about the intricacies of working with dual-symbol devices and understand how to manage the priorities of networks, while maintaining access to the mobile Internet through another active card.
Why you need software disabling SIM-card
The main reason for deactivating the SIM card software is to save battery power. Finding a network in areas with unstable coverage makes the smartphone modem work at its limit, which significantly reduces battery life. By disabling an unused card, you reduce the load on the communication processor.
Another important aspect is financial control: While abroad, a user can leave one card active to receive SMS from the bank, and a second card that can accidentally connect to expensive roaming completely disables in the settings, which is more reliable than just not making calls, since background processes can sometimes initiate a connection.
Also worth mentioning are situations where interference needs to be eliminated: sometimes, when testing communication quality or setting up certain applications, only one line is required to be active in the system, software shutdown does not reset network settings and saves all contacts associated with the card.
⚠️ Note: When you turn off the SIM card through the settings, all incoming calls and messages to this number will stop coming. The sender will see the status of "subscriber unavailable" or "off».
There are several scenarios for using this function, which can be divided by the degree of need:
- 📉 Reducing energy consumption in extreme operating conditions.
- 💰 Blocking paid services and roaming for the second SIM card.
- 🔇 Creating a “work-only” or “personal call only” mode».
- 🔧 Diagnosing problems with mobile internet or calls.
Step-by-step instructions for MIUI and HyperOS
Xiaomi’s shell interface may vary slightly depending on the Android version and regional firmware, but the logic remains the same. First, you need to go to the main settings menu of the device. Usually the icon is geared and located on the desktop or in the notification curtain.
Find the partition that connects to the network. Most current versions call it «SIM-Maps and mobile networks, or simply Mobile Network, is where all the levers of control over the physical communication modules of your smartphone are concentrated.
Inside this menu, you'll see a list of SIM cards installed, each signed as SIM 1 and SIM 2, or a user name if you've asked it before, and next to the card name is a switch that lets you activate or deactivate the module.
☑️ Algorithm of disabling SIM card
Once the slider has switched to an inactive state, the system can request confirmation of the action, accept the warning, and the network icon in the status bar will disappear or change, showing that only one card is now active, the process takes no more than 10-15 seconds.
Managing two SIM cards at the same time
Xiaomi smartphones support the full operation of two active SIM cards at the same time, but the settings allow you to flexibly manage their behavior «SIM-Maps and mobile networks can not only turn off cards, but also assign their default role for various types of traffic.
It is important to distinguish between “disable SIM card” and “disable data transfer.” You can keep the card active for voice and SMS, but prevent it from using mobile Internet, this is done in the subsection “Mobile Internet” or “Data transfer”, where you select the priority card.
There's also a separate setting for calls, so you can set a specific SIM card for all outgoing calls, or leave the "Always Ask" option, which allows you to keep the second card on for important calls, but not use it for outgoing activity.
| Parameter | SIM card 1 | SIM card 2 | The result |
|---|---|---|---|
| Status | Included. | Off. | Only the SIM 1 works. |
| Mobile Internet | Included. | Off. | Internet only via SIM 1 |
| Voice calls | By default. | Disconnected. | Calls via SIM 1 |
| SMS | By default. | Disconnected. | Messages via SIM 1 |
This flexibility allows you to create complex use cases, for example, one card can be allocated exclusively for instant messengers and the Internet, and the second card is only for voice calls, both of which will be active and available for incoming.
What happens to the contacts on the disabled SIM card?
Flight mode and its difference from switching off SIM
Many users confuse switching off the SIM card with activating flight mode, which differs dramatically in its effect on the device, and Airplane Mode completely disables all wireless interfaces: Bluetooth, Wi-Fi, NFC and cellular modules.
When you turn off the SIM card through the settings menu, the cellular module for that card stops working, but other smartphone features remain available. GPS-navigation without restrictions.
Flight mode is only useful in situations where there is a need for complete absence of radiation or a quick reboot of the network module. For everyday management of costs and calls, it is preferable to use individual management of each SIM card.
⚠️ Note: In flight mode, emergency calls (112, 911) may not be available, while when one SIM card is software disabled, calls via another active card or even without a card (if the operator allows) are possible.
If your goal is to simply save power by turning off one of the cards but staying online via Wi-Fi, then flight mode will not suit you, in which case the correct solution is to selectively disable the SIM card in the corresponding menu section.
Decision and activation errors
Sometimes users are faced with a situation where the SIM card does not turn on after the software shutdown, the slider in the settings can be gray or return to the original position, most often due to a temporary failure in the services of the MIUI operating system.
The first step in this situation should be to simply reboot the device, which updates the modem configuration and resets the temporary errors. If the problem persists after the smartphone is turned on, check if the card is installed in a special slot limited only to 2G/3G networks on some older models.
Another reason could be damage to the SIM card contacts themselves or contamination of the tray. Although we're talking about disconnection without retrieval, the physical factor cannot be discounted. Try gently wipe the SIM card contacts with a soft cloth if you can remove it.
- 🔄 Perform a full reboot of the smartphone.
- 🔍 Check the correct installation of the SIM card in the tray.
- ⚙️ Reset network settings to factory values.
- 📱 Update the device to the latest version.
In rare cases, the problem lies in the software conflict of the applications that manage calls. If you have installed third-party dialers or applications to record calls, try to remove them and check the standard interface.
💡
If the SIM card slider is inactive (grey), try to turn flight mode on and off first.This often restarts the network stack and returns control to the slider.
Impact on the work of messengers and applications
Disabling your SIM card directly affects the operation of applications tied to your phone number, and messengers like WhatsApp, Viber or Telegram may require re-verification if you disable the card you have registered to, although they often continue to work over Wi-Fi.
Banking applications that use SIM-map SMS-The confirmation codes will no longer function fully. SMS to the disabled card until you activate it again in the settings.
It's important to understand the difference between "no network" and "card off." For most applications, this is the equivalent of a communication channel with the operator being blocked. So before important operations requiring SMS confirmation, make sure that the SIM card you need is active.
Background data synchronization that does not require mobile Internet (for example, via Wi-Fi) will continue to work. However, push notifications that depend on the operator's channel (some types of communication). SMS-notifications, will not be received.
💡
Disabling the SIM card does not software delete data from the chip and does not affect the operation of applications using Wi-Fi, but blocks the receipt of SMS and calls to this number.