Modern Xiaomi smartphones provide users with ample opportunities to manage network connections, allowing them to flexibly configure the operation of communication modules without the need for physical intervention. Situations when you need to temporarily deactivate one of the SIM cards, arise quite often: whether it is saving battery power in the low signal zone, the need to use only Wi-Fi Calling or simply a desire to take a break from calls, while maintaining access to the Internet through the second card. Software shutdown is the safest and most convenient method that does not require finding a clip to extract the tray and the risk of damaging mechanical contacts.
In the operating system MIUI New HyperOS implemented advanced management functionality SIM-It's important to distinguish between "disable the map" and "disable data" because these functions are responsible for different aspects of the device's operation. In this article, we will discuss how to properly deactivate voice calls and SMS specific SIM, leaving the second active, and also consider the nuances of working with PIN-energy saving codes and modes.
Using software-based SIM management techniques on Redmi and Poco allows you to instantly switch between usage profiles, such as turning off your work SIM card on weekends while keeping your personal SIM active, or vice versa, especially for dual-sim smartphone owners, where balancing personal and workspace requires clear lines of communication.
Management SIM-maps through system settings MIUI
The most common and recommended way to deactivate a SIM card is to use the built-in operating system interface. Xiaomi developers have provided a separate section in the settings, which allows you to manage each card individually. To access this functionality, you need to go to the Settings menu, then select the item SIM-Maps and mobile networks. This shows both cards installed if the device tray supports Dual-SIM.
In the list that opens, you'll see switches opposite each of the SIM cards. Moving the slider to an inactive state instantly disconnects the card from the operator's network. At this point, the smartphone stops registering on the cellular network for this profile, which leads to the disappearance of the signal level in the status bar. It is important to understand that the second SIM card continues to work normally, receiving calls and SMS.
⚠️ Note: After the software disables the SIM card, incoming calls to this number will be unavailable, and the subscriber will hear the operator’s standard message that the phone is turned off or is out of range of the network.
The management interface may vary slightly depending on the firmware version. In older versions of MIUI, the switch can be located inside the settings menu of each individual card, whereas in HyperOS, control is brought to the upper level for convenience. If you can't find the right switch, search by settings by typing "SIM".
It is worth noting that software shutdown does not reset network settings and does not require re-authorization when enabled unless installed. PIN-This makes it ideal for frequent use, but if you have a map on it. PIN-code, when activated again, the system may request its input to confirm your actions.
Using flight mode to temporarily lock
Flight mode, or "Air mode", is a radical but effective way to disable all wireless interfaces at once. Activating this function through the notification curtain or Settings menu → Connections and sharing completely blocks the radio module, as a result of which both SIM cards stop searching for the network, Bluetooth and Wi-Fi are turned off (although Wi-Fi can be turned on forcibly after activation of the air mode).
This method is useful in situations where complete isolation from the outside world or a quick reboot of the network module is required to eliminate login errors in the network. For example, if the phone has "lost" the network and does not see the operator, a short-term on and off flight mode often helps to re-register the network without restarting the entire device.
- ✈️ Instantly shuts off all radiofrequency radiation, which can be important in aircraft or medical facilities.
- 🔋 Significantly saves battery power, as the smartphone stops spending energy on the search for base stations.
- 📶 Allows you to quickly reset network settings and eliminate software communication failures.
But there's a big drawback to this method: it turns off all SIM cards at once, and if your goal is to turn off only one card, leaving the other card active for important calls, you're not going to be in a flight mode, so you'd better use customized control through the settings menu described in the previous section.
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Use flight mode for 10-15 seconds to quickly reset network settings if the signal or the Internet is missing, instead of a full reboot of the smartphone.
In some use cases, such as nighttime rest, users combine flight mode with an alarm clock. Since the alarm clock in Xiaomi works even when the radio module is turned off, this ensures that you wake up on time, but no one disturbs you with a call.
Lockdown SIM-map PIN-code
A deeper level of protection and disabling the SIM card involves the use of PIN-If you activate the request PIN-When you turn on your phone, the SIM card will be completely locked until the correct code is entered, and this is an effective way to protect the data on the card and prevent unauthorized use of the number in the event of theft of the device.
To set up this function, go to Settings → Protection and security → Confidentiality → Lockdown SIM-You can activate the request here. PIN-Once you have this option enabled each time you reboot your smartphone or reset and reset the card, the system will require you to enter the code. Without entering the code, the card remains in the "Disable" state and does not work.
| Parameter | Description | Recommended value |
|---|---|---|
| Request. PIN-code | Requirement for code entry at start | Included. |
| Standard PIN | Default code from the operator | 0000 or 1234 |
| PUK-code | Unlock code when PIN error | Store separately |
| Maximum attempts | Limit of erroneous inputs | 3 attempts at |
It's important to distinguish PIN-code PUK-code. PIN-The code (usually 4 digits) is used for daily unlocking. PUK-8 digits code is required if you enter three times incorrectly PIN-Input incorrectly PUK-10 times leads to irreversible blocking of the SIM card, and it will have to be restored in the cabin of the operator with a passport.
⚠️ Warning: Never keep it. PIN and PUK codes in notes on your phone or in the cloud without protection, you'd better write them down on paper and store them in a safe place separate from the device.
Use of the PIN-The code actually turns the SIM card off until the user confirms their identity, and it's the only method that ensures that even if you move the card to another phone without your knowledge, it won't work.
Disabling data transfer for a specific SIM
Often users do not need to completely disable the SIM card, but only a ban on the use of mobile Internet through it to avoid debiting funds or roaming costs. In Xiaomi smartphones, you can flexibly configure which card is used for data transfer, and which is only for voice calls and SMS.
On the menu. SIM-maps and mobile networks have the option Mobile Internet (or "Use by default"SIM 1" or"SIM 2" you guarantee that Internet traffic will only go through the selected profile. The second card will remain active for calls, but will not waste traffic.
- 📉 Prevents background updates of applications over an expensive network.
- 🌍 Ideal for travel when one card is local (for the Internet) and the second is home (for reception only). SMS bank-like).
- ⚙️ Allows you to save push notifications that can come through the communication channels of the second SIM card (if the operator supports the).
Additionally, mobile network settings can disable data roaming. Even if data transfer is enabled, the roaming ban will prevent the phone from connecting to the Internet via foreign networks, which will save your balance from unexpected expenses.
What is VoLTE and how does it affect shutdown?
It’s worth remembering that some apps may try to use the mobile network even if you’ve set a priority on Wi-Fi. For full control, it’s recommended to use the built-in traffic monitor in the Xiaomi Security app, where you can deny access to the mobile network for specific applications.
Problems with displaying and switching SIM cards
MIUI users sometimes experience a situation where the SIM card is displayed as "Unknown" or the switch does not respond to clicks, this can be caused by a software failure of the telephony service or malfunctioning of system updates, in which case simply switching the slider in the settings menu may not work.
The first step in diagnosis is to check the physical contact. Despite the topic of the article "without taking out", sometimes it helps to lightly tap the tray area (if the design of the case allows) to make sure that the card has not moved away from the contacts. If physical exposure does not help, try resetting the network settings. Way: Settings → Connection and Sharing → Reset Wi-Fi, mobile networks and Bluetooth.
This procedure won't delete your personal data, photos or contacts, but it will reset all network settings to factory settings. Once you reboot, the phone reads the SIM card data again and registers online, often solving the problem of "stuck" status of the SIM card.
☑️ Diagnosing problems with SIM-card
If the problem persists, it may be a software conflict, and check if you have third-party applications for managing calls or a twin SIM, which can intercept control of the communication module and block regular system functions.
Alternative Methods and Engineering Menu
For advanced users, there is an engineering menu where you can control the radio module at a deeper level, and you can log in to the engineering menu via a dialer code, such as ##4636##. However, on modern versions of MIUI, this code is often blocked or requires the installation of a special activator application.
In the engineering menu, you can find the Phone Information section, where the status of each of the devices is displayed. SIM-There may be a Turn off radio or similar button that forcibly shuts down the radio module, and this method is not recommended for ordinary users, because incorrect actions can lead to loss of radio. IMEI or unstable phone operation.
⚠️ Warning: Changing the settings in the engineering menu without understanding their exact purpose can lead to complete loss of communication.
A safer alternative is to use automation scenarios, applications like Tasker or built-in scripts in MIUI allow you to create automatic rules, for example, you can configure a scenario: "If it's 23:00 → Turn off SIM 2." This allows the automatizers to turn off the process without you.
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The safest and most stable way to disable a SIM card is to use a regular switch in MIUI settings, rather than third-party applications or engineering codes.
Xiaomi’s ecosystem thus provides a sufficient set of tools for flexible SIM card management, from a simple switch in settings to complex automation scenarios, each user can choose the method that suits their use case.