Setup SIM- cards and mobile networks in Xiaomi smartphones: from installation to optimization

Xiaomi smartphones support one or two SIM- cards (depending on the model), but even experienced users sometimes face problems when setting them up. Lack of network, slow Internet, registration errors or incorrect settings APN — these and other difficulties can turn a simple procedure into a time puzzle. In this article, we will discuss all the steps of working with SIM- cards in Xiaomi devices, Redmi and POCO: from physical installation to fine-tuning of mobile Internet and calls.

We will pay special attention to the common mistakes that users make when they first turn on the phone. For example, many people don’t know that dual-sim models (such as the Xiaomi 13 Pro or Redmi Note 12) can assign a priority SIM- card for data, as well as separately configure the settings for calls and SMS. We will also discuss how to check the compatibility of your SIM- card with the 4G/5G network and what to do if the phone does not see the operator.

This article is relevant for all modern Xiaomi devices based on MIUI 12-14 and HyperOS, including flagship models (Xiaomi 14, Xiaomi 13 Ultra) and budget series (Redmi A2, POCO M6 Pro).If you just bought a smartphone or faced communication problems, here you will find step-by-step solutions with illustrations and screenshots of the menu.

1. Selection and preparation of SIM- card for Xiaomi

Before installing the SIM- card in a Xiaomi smartphone, make sure it meets three key requirements:

• 📱 Form factor: Most current models (Xiaomi 12T, Redmi Note 11) support nano-SIM (4FF). Older devices (e.g. Redmi 4X) may require micro-SIM (3FF).
• 🌐 Network Compatibility: If your carrier supports VoLTE (voice over 4G) or 5G, check if these features are unlocked in firmware. For example, POCO F5 5G runs out of the box, and some regional versions of Redmi 10 may require manual activation.
• 🔄 Two-sim: If you use two SIM- cards, one of them can only work in 2G mode (in hybrid slot models, such as the Xiaomi 11 Lite NE).

If you are switching from another phone, don't cut out the old SIM- card yourself - you'd better ask for a new one from the operator. Incorrect cropping can damage the chip and the card will cease to be identified.

• 🔌 Hybrid slot (SIM + microSD): In this case, when you install the second SIM- card, you lose the ability to use the memory card (relevant to Redmi 9A, POCO M4 Pro).
• 🔌 Two separate slots (SIM + SIM + microSD): support both SIM- cards and a memory card at the same time (e.g., Xiaomi 13 Lite).

⚠️ Warning: If you use an eSIM (virtual SIM- card, note that not all Xiaomi models support it. At the time of 2026 year, eSIM is only available in the Xiaomi 13/14 series, Xiaomi 12T Pro and some versions of POCO F4 GT. Check the carrier's compatibility.

2. Installation of SIM-card in the smartphone Xiaomi

The process of installing a SIM- card seems simple, but many users make mistakes that then lead to loss of the network or damage to the slot.

1. Turn off your phone. This is a must, even if the instructions say you can install the card on the device on, and a hot change can cause the communication module to fail.
2. Find the tray for the SIM- card. Usually it is located on the upper or lateral face of the smartphone. In the POCO X3 Pro and Redmi K50 models, the slot is on the right, in the Xiaomi 12S Ultra is on the top.
3. Use a paper clip or a special key (companyed) to remove the tray. Do not use needles or toothpicks - they can damage the mechanism.
4. Place the SIM- card in the tray with the contacts down, combining the bevelled corner of the card with the slot angle. For two-symbol models, use the SIM1 and SIM2 tags on the tray.
5. Carefully insert the tray back before the click. Don't apply force - if it doesn't come in, check if the card is installed correctly.

After turning on the phone, wait for the network icon to appear (usually it takes 10-30 seconds).

• 🔄 Reset the device.
• 📶 Check if flight mode is enabled (Settings → Connections → Flight mode).
• 🛠️ Remove and install the SIM- card again — the contacts may not be in contact.

If the phone still doesn’t see the SIM- card, the problem may be a slot malfunction or a IMEI lock (relevant for devices purchased abroad).

3. Setting up the mobile network and the Internet

Once the SIM- card is successfully installed, you need to configure mobile internet and network settings, and most of the time, the settings are automatically applied, but sometimes manual configuration is required.

Go to the Settings menu of → SIM-maps and mobile networks, and here you will see all the SIM-maps installed. Click on the map you want and do the following:

1. Enable mobile data (slider at the top of the screen).
2. Choose the network type: 2G – only calls and SMS (minimum power consumption); 3G – Internet and calls (an outdated standard, but still used in some regions); 4G (LTE) – the best choice for most users. 5G – is available only on supported models (Xiaomi 13 Pro, POCO F5 Pro, etc.) and with operator coverage.

Access Points (APN)

Access Points (APN)

Add an access point

MTS

Name: MTS


APN: internet.mts.ru




User name: mts




Password: mts

If you use two of them SIM-maps, in the menu Settings → SIM-maps and mobile networks → Mobile data can be selected as the primary data for the Internet, and priority for calls is set (e.g., you can make outgoing calls always go through the Internet). SIM1).

⚠️ Warning: If the internet is still down after setting up APN, check your account balance and plan activity. Some operators block access to the network when there is a negative balance, even if there is money in the account.

4. set up VoLTE and VoWiFi in Xiaomi

VoLTE (voice over 4G) and VoWiFi (wi-fi calls) are significantly improving communication quality, especially in areas with poor coverage.

To activate them:

1. Go to Settings. → SIM-maps and mobile networks.
2. Choose the right one. SIM-map.
3. Activate sliders: VoLTE – calls over 4G (improving voice quality and reducing connection time); VoWiFi – calls over Wi-Fi (useful if the mobile network is weak, but there is stable Wi-Fi).

If VoLTE or VoWiFi options are not on the menu, this could mean:

• 📵 Your operator does not support these technologies (check the operator's website).
• 🔧 Your Xiaomi model is not certified to work with VoLTE in your region (relevant for gray devices purchased abroad).
• 📱 You have an outdated firmware version. Update MIUI or HyperOS to the latest version.

In the Xiaomi 12/13/14 series and POCO F4/F5, when VoLTE is activated, Enhanced 4G (LTE+) automatically turns on, which speeds up the loading of data during a conversation.

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If VoLTE calls start to stop after you turn on, try turning it off and use standard 3G mode for voice communication, sometimes because of unstable 4G coverage in your area.

5 Solving Common Problems with SIM- Cards

Even after installing and configuring the SIM- cards correctly, Xiaomi users may encounter errors.

5.1 Phone does not see SIM- card

If the smartphone does not define the SIM- card:

• 🔄 Reset the device.
• 📶 Check if flight mode or power saving mode is on (the communication module may turn off).
• 🛠️ Remove and reset the SIM- card, and if that doesn't work, try inserting it into another smartphone -- maybe the problem is with the card itself.
• 📲 Update the firmware: go to Settings → The phone. → Updating the system.
• 🔧 Reset network settings: Settings → SIM-maps and mobile networks → Resetting network settings.

5.2 No mobile Internet

If the network icon is available, but the Internet is not working:

• 🌐 Check the settings APN (see Section 3).
• 📡 Make sure that mobile data is enabled for the desired SIM- card.
• 🔄 Switch the network mode from 4G on 3G back and forth.
• 📵 Check the balance and activity of the tariff plan with the operator.

Poor quality of communication or call interruptions

If there is interference or connection interrupted during the conversation:

• 📶 Turn off VoLTE and try calling in 3G mode.
• 🔋 Check the signal strength, if it's weak (1-2 divisions), try moving closer to the window or going outside.
• 🛠️ Update the radio module (if an update is available via Settings → About Phone → System Update).

⚠️ Warning: If the network problem only occurs in a specific location (e.g., at home), interference from other devices (routers, microwaves) or poor coverage of the operator may be the cause, in which case only a change of operator or a signal repeater installation will help.

6 Optimization of two SIM- cards

If you are using two SIM- cards in Xiaomi, it is important to properly configure their interaction to avoid conflicts.

• 📞 Assign a primary SIM- card for calls: to Settings → SIM-maps and mobile networks → Call settings, select which card to use by default.
• 🌐 Separate Internet and calls: for example, you can make mobile Internet work through SIM1 and calls through SIM2.
• 🔋 Turn off mobile data for the second SIM- card if it's only used for calls. This will save battery life.
• 📵 Set up incoming call notifications: in Settings → SIM-maps and mobile networks → Call notifications can enable missed call alerts on both SIM-maps.

Some models (e.g., Xiaomi 13 Pro or POCO F5) offer a dual Standby feature that allows both SIM- cards to stay online at the same time. However, in 4G Double Activity (DSDS), one card can temporarily disconnect from the network while the other is in active use. This is normal behavior, it cannot be changed software.

If you want both SIM- cards to be always connected, select 3G/2G mode for the second card in your network settings, which will reduce Internet speed but ensure stable call operation.

7. 5G setup in supported Xiaomi models

Xiaomi 5G-enabled smartphones (e.g., Xiaomi 13 Pro, POCO F5, Redmi K60) require additional customization for maximum internet speed.

1. Make sure your SIM- card supports 5G. For this, contact the operator or check on the site (for example, MTS, Beeline or MegaFon have lists of compatible rates).
2. Go to Settings → SIM- Cards and Mobile Networks → Network Type and select 5G.
3. If you don’t have a 5G option, upgrade to the latest version of MIUI or HyperOS.
4. Check 5G coverage in your area. Even if the phone supports that network, it may not be available in your city.

In some cases, activation of 5G requires manual addition of APN. For example, for Tele2, use the following options:

Name: Tele2 5G


APN: internet.tele2.ru




Type APN: default,supl




Protocol: IPv4/IPv6

The Xiaomi 14 and POCO F6 Pro models have a “Smart 5G” feature that automatically switches between 4G and 5G depending on the network load, saving battery life.

💡

If the phone starts to run faster after 5G is turned on, turn off this feature in the network settings. The 5G module consumes more power, especially in low signal conditions.

8. Network settings reset and extreme measures

If none of the above methods helped solve the problem with the SIM- card or mobile network, you may need to reset the network settings, which will return all communication parameters to factory values, but will not affect personal data (photos, contacts, applications).

To perform the discharge:

1. Go to Settings. → SIM-maps and mobile networks → Resetting network settings.
2. Confirm the action by entering a password or pattern lock.
3. After the reset, the phone will reboot and you will need to reconfigure the APN and other settings.

If the reset did not help, the problem may be:

• 🔧 Hardware malfunction (damaged SIM- card slot or antenna module).
• 📱 Lock IMEI (relevant for devices imported from abroad).
• 📡 Problems with the operator (for example, technical work at the station).

In these cases, it is recommended that:

• Contact the Xiaomi Service Center for Diagnostics.
• Call your mobile operator to check if there are any restrictions on your number.
• Try inserting the SIM- card into another phone to make sure it works.

⚠️ Warning: If you bought a Xiaomi smartphone abroad (e.g. in China), it IMEI may be blocked to work in Russian networks, in which case you will need official unlocking through a service center or a seller.

FAQ: Frequent questions about SIM-maps in Xiaomi