How to turn off the SIM card on Xiaomi Redmi 9

Managing communication modules on Xiaomi smartphones is often required in a variety of life situations, from saving battery power to temporarily blocking incoming calls. The Redmi 9 model features a modern MIUI shell that provides flexible tools to configure network connections. The user does not always need to fully remove the chip from the device, since software shutdown solves most tasks instantly.

In the Android operating system that runs Redmi 9, the process of deactivating the SIM card is implemented through system settings, which allows you to save contacts and data on the media by temporarily stopping registration in the operator's network. It is important to understand the difference between software disabling and physical extraction, since the algorithms of actions are significantly different.

This article describes in detail all the available ways to manage SIM cards in the device, we will look at the standard settings menu, quick actions through the control panel and the features of working with two slots at the same time, and will also touch on the nuances that will help to avoid loss of communication at a critical moment.

Before you start changing the settings, make sure you understand the consequences of these actions. SMS-The operator will consider the subscriber unavailable, which can be critical for important notifications from banks or delivery services.

Software Disconnection through Network Settings

The main and most correct way to manage SIM cards is in the back of the system menu, which allows you to selectively deactivate one of the slots without affecting the second, which is especially important for owners of two-symbol versions of Redmi 9.

In the list of parameters that opens, you should find the section responsible for wireless connections. MIUI, it could be called «SIM-Maps and mobile networks, or simply Mobile Network, is where all the levers of control over the communication modules of your smartphone are concentrated.

Once you log in, you'll see a list of SIM cards installed, each signed as SIM 1 or SIM 2, and it can have a user name if you've asked it before, and next to each slot is a switch switch switching switch, which is responsible for activating or deactivating the module.

When you switch the switch to the inactive state, the system will give a warning that the phone will become unavailable for calls. Once you confirm the action, you will see that the signal level indicator in the status bar has disappeared for the selected slot, now mobile Internet and voice communication through this number will not work.

Using flight mode for fast locking

There is a more radical but quick method of shutting down all network connections, flight mode, which was originally designed for air travel to prevent interference with the aircraft's navigation equipment. On Redmi 9, activating this mode instantly shuts down all wireless modules, including Bluetooth, Wi-Fi and cellular communications.

To use this method, just swipe down to open the notification curtain. In the quick settings panel, you need to find the icon of the aircraft and click on it. The screen of the smartphone can blink, and in the status bar will appear the corresponding icon, signaling the complete isolation of the device from external networks.

⚠️ Warning: Flight mode shuts down all SIM cards at once. If you need to keep one number active for emergency communication, this method will not work, since it blocks both slots at the same time.

The advantage of this method is speed, and in situations where you need to immediately stop radiation from the phone or block incoming calls from all numbers, this is the optimal solution, but for selective control you will have to use the settings menu described in the previous section.

You can't take a call through messengers or use a navigator if the cards weren't downloaded in advance, so use this tool with an understanding of its wide range of action.

Managing two SIM cards at the same time

Xiaomi Redmi 9 supports two Nano-SIM SIM cards. This creates certain nuances in the management, as the user can be confused which slot he turned off. The system allows you to assign names to cards, for example, “Work” and “Personal”, which makes navigation easier.

In the SIM management menu, you can not only turn them on and off, but also set priorities, for example, you can set the use of one card only for data transfer, and the second one for voice calls, which helps optimize communication costs if the tariff plans of different operators differ.

If you turn off one of the SIM cards, the second one will continue to work normally, and you will only see one network indicator in the status bar, which is convenient when one of the carriers has poor coverage in your current location, and the phone is constantly trying to find the network, using up the battery.

When switching between slots, the system may require a short pause to re-register on the network. Don't panic if the second SIM card does not immediately turn on the Internet. The process of establishing handshake with the operator's base station can take from a few seconds to a minute.

Physical extraction of the SIM card tray

Sometimes software shutdown is not required, and it becomes necessary to completely remove the media from the device, this may be necessary to install a new SIM card or when selling a phone. On Redmi 9, the SIM card tray is combined with a microSD card slot.

Removing the tray will require a special metal clip that comes with the kit, or a thin needle. On the end of the smartphone, usually at the bottom or side, there is a small hole next to the elongated tray. You need to gently press the clip into the hole until the characteristic click.

The tray will extend a few millimeters, and then you can take it out with your fingers. Notice the orientation of the SIM card, which has to be in the recess, bent angle to a certain direction. The tray itself often has a schematic image that tells you the correct position.

Once the card is removed, the phone will automatically detect the configuration change and notify you of it. If you plan to store the SIM card separately, it is recommended to remove it in a special plastic envelope so as not to damage the contacts and not lose it.

Problems with determining the SIM card after switching on

There are situations when, after the SIM card is turned on, the phone does not see the network or writes "No service", this can be due to a temporary malfunction of the Redmi 9 radio module. Most often, the problem is solved by simply restarting the device, which resets all temporary software errors.

Another cause could be contamination of the contacts on the SIM card itself or in the tray, and over time, oxide film or dust forms on the golden contacts, and careful wiping of the contacts with soft cloth or eraser can restore the connection.

It is also worth checking if the SIM card is installed. PIN-If the code is on, every time you turn on your phone or activate your SIM card, the system will ask you to enter it, and without the right code, you will be blocked for security reasons.

⚠️ Note: Three times incorrect input PIN-The code will block the SIM card permanently. PUK-code that can be found on a plastic card holder issued when buying a SIM card.

If the SIM card is old and has been used on different phones for many years, it may be physically worn out, in which case it is advisable to contact the operator’s salon for a free replacement of the SIM card with a new one, while saving the number.

The impact of disabling the SIM card on the operation of applications

Many users don't realize that turning off a SIM card doesn't just affect calls. Some apps, especially banking and instant messengers, use a phone number for identification or two-factor authentication. SMS-Confirmation codes will be impossible.

Taxi and delivery apps can also behave incorrectly if they are tied to a specific number that you have temporarily disabled.The Driver may not contact you, and the system may not be able to confirm your location through cell towers if both GPS and mobile internet are disabled.

On the other hand, turning off the SIM card helps save battery power. Constantly searching for the network in areas of uncertain reception is one of the most energy-intensive processes for a smartphone. If you are in a place where there is no connection, but Wi-Fi is working, turning off the mobile network will prolong the life of the Redmi 9.

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Use the Wi-Fi Only feature in your mobile network settings if you want to keep your SIM card active for calls, but prevent apps from using mobile internet to transfer data.

It is also important to consider that some MIUI features, such as cloud contact synchronization or phone search, may require an active network connection. Although they work over Wi-Fi, the lack of a SIM card can change the priorities of a device's network activity.

Frequently Asked Questions (FAQ)

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Software-based SIM card disabling is a safe and reversible operation that does not delete data or harm the device, allowing flexible management of costs and connections.