Function DUO Xiaomi Redmi: detailed explanation and configuration

If you are the owner of a Xiaomi Redmi smartphone and notice a mention of the function in the settings or on the box DUO, But you don't understand what it is -- you're not alone. Many people confuse this technology with the regular Dual. SIM (Two SIM cards, but in fact, DUO Offers a more flexible solution for multi-number and networking.

In this article, we will understand what is DUO Xiaomi Redmi as it differs from standard Dual SIM, What models support this feature and how to set it up correctly, and you will also learn about the possible problems and limitations that you may encounter when using it. DUO, Get practical tips on optimizing your work with two SIM cards.

This information will be especially useful for those who travel frequently, use work and personal numbers on the same device, or want to save on roaming.

What is it? DUO Xiaomi Redmi and how it works

Function DUO (Dual on Xiaomi Redmi smartphones is an improved version of Dual technology SIM, It allows you to use two SIM cards at the same time, but with a number of additional features. SIM, where both cards are working DSDS (Dual SIM Dual Standby), DUO frequently DSDA (Dual SIM Dual Active) or hybrid schemes.

The main difference is that when DSDS (standard-setting SIM) One of the SIM cards is temporarily disabled when the other is active (for example, during a call). DUO Both SIM cards can be active at the same time, which allows them to:

• 📞 Accept calls to both SIM cards without passes (if supported) DSDA).
• 📶 Use mobile internet from one SIM card while the other is receiving calls.
• 🔄 Switch between networks without rebooting.
• 🌍 Optimize roaming (for example, use a local SIM card for the Internet, and the main one for calls).

It is important to understand that DUO — It's not a separate module, but a hardware and software solution that Xiaomi integrates into its smartphones, and it can work in different ways depending on the model and the firmware version. MIUI. For example, in some devices DUO Implemented through a hybrid slot (one nano-SIM) + microSD or the second nano-SIM, and in the other two full slots.

Differences DUO classic Dual SIM

Many people mistakenly believe that DUO dual SIM — They're the same thing. In fact, there are key differences between them that affect usability:

Main advantage DUO — It's the ability to flexibly manage two SIM cards without any restrictions:

• 📱 Automatic Switch to SIM Card with Better Signal.
• 💼 Separation of contacts by SIM cards (working and personal).
• 🌐 Using one SIM card for the Internet and the other for calls.

But there are some nuances, such as some Redmi models, where a single SIM card activates the mobile internet, the second card may temporarily disconnect from the network. 4G/5G. It depends on the hardware implementation and version. MIUI.

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If your Redmi supports you DUO, but you don’t see options for flexible customization, upgrade to the latest version MIUI. Often new features appear in updates.

What Xiaomi Redmi models support DUO

Function DUO Not all Xiaomi Redmi smartphones are available, but it is usually found in mid- and premium models released after 2020. DUO:

• 📱 Redmi Note 11 Pro/Pro+ (hybrid slot, support 5G on both SIM cards in some regions).
• 📱 Redmi Note 12 Pro/Pro+ (full-fledged DSDA, Both SIM cards are active at the same time).
• 📱 Redmi K50/K50 Pro (support) 5G on both SIM cards, advanced settings DUO).
• 📱 Redmi 10 2022 (hybrid slot, basic version) DUO).
• 📱 POCO X4 Pro 5G (Similar to the Redmi Note 11 Pro, but with other default settings).

To know if your model supports you DUO, Follow the following steps:

1. Go to Settings → About the phone → All the characteristics.
2. Find the SIM card or Network section.
3. If you see a mention DUO, DSDA or dual SIM Dual Active – Your device supports the technology.

You can also check the box or the official page of the model on the Xiaomi website) DUO It can work differently than in global versions of smartphones.

How to set up DUO Xiaomi Redmi: step-by-step instructions

Setting up DUO Xiaomi Redmi is usually easy to handle, but there are a few nuances to be aware of:

1. Insert the SIM card. If you have a hybrid slot, choose the priority: either two SIM cards or one SIM card. + Note that in some models (e.g. Redmi Note 10) when using two SIM cards, the microSD slot is blocked.
2. Activate the SIM card. Go to Settings. → SIM cards and mobile networks → Management SIM-If one of them is not identified, check the installation correctly or try to restart the device.
3. Set your priorities. Select the same menu: 📞 SIM card by default for calls (you can select "Ask always"). 💬 SIM card by default for SMS. 🌐 SIM card for mobile data (important for saving traffic).

Set up network switching.

In the Mobile Network section, you can select the preferred network type for each SIM card (for example, 4G one-and-one 5G for the other, if maintained).

If you want to be more flexible, DUO, Pay attention to additional settings:

• 🔄 Automatic data switching – allows you to use mobile Internet from a SIM card that has a better signal.
• 📡 Improved roaming – useful for travel (setting is not available on all models).
• 🔒 Switching ban – fixes the use of one SIM card for the Internet.

Inserted both SIM cards (or one SIM card) + eSIM)

Both SIM cards are activated in the settings

Default SIM cards assigned for calls/SMS/internet

Checked network signal on both SIM cards-->

After setting up, it is recommended to restart the smartphone so that the changes take effect. If one of the SIM cards does not catch the network, try manually selecting the operator in the settings or updating the firmware.

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In the models with MIUI 14 and newer settings DUO can be in the Connections and Sharing section instead of SIM cards and mobile networks.

Common problems with DUO and their decisions

Despite the convenience, the function DUO It's sometimes unstable. Here are the most common problems and the ways to solve them:

⚠️ Note: If after setting up DUO The phone started to run out quickly, check if you're constantly searching for the network on both SIM cards.

If none of these methods worked, try:

1. Reset network settings (Settings) → SIM cards and mobile networks → Resetting network settings).
2. Update the firmware to the latest version (via Settings → System Update).
3. Contact Xiaomi or carrier support for diagnostics.

In some cases, the problem may be regional firmware, such as if you bought a smartphone in China and use it in Russia, there may be conflicts with local networks, the solution being to install global firmware (but this requires unlocking the bootloader and may be unwarranted).

DUO and eSIM: Can I use it together?

Many modern smartphones Xiaomi Redmi supports not only physical SIM cards, but also eSIM (built-in SIM card). DUO The answer is yes, but with reservations.

In most models (for example, Redmi Note 12 Pro)+ Xiaomi 13 can be used for this purpose:

• 📱 One physical SIM card. + one-off.
• 📱 Two physical SIM cards (unless the slot is hybrid).

However, two eSIMs are simultaneously + Physical SIM cards are not usually supported, and it is worth considering that not all operators in Russia and the CIS provide eSIM services for individuals (for 2026 this is mainly MTS, Beeline and Tele2 in test mode).

To set up the eSIM together with DUO:

1. Get it from the operator. QR-code or data for activating eSIM.
2. Go to Settings. → SIM cards and mobile networks → Add eSIM.
3. Scan it. QR-code or enter data manually.
4. Assign eSIM as the primary or secondary SIM card in the settings DUO.

If the physical SIM card stopped working after activation of eSIM, check if they are not conflicting over the issue. IMSI-Profile: In some cases, rebooting or resetting network settings helps.

Advice on optimizing the work with DUO Xiaomi Redmi

To use it as efficiently as possible DUO On your Xiaomi Redmi, follow these tips:

• 🔋 Battery savings: If you don’t need constant access to both networks, turn off network search for the second SIM card in settings (Settings) → SIM cards. → [sim-card] → Searching the net → Manually).
• 🌍 Roaming: When traveling, set up automatic switching to a local SIM card for the Internet, and leave the main one for calls.
• 📵 Priority of calls: In settings DUO Select the Always Ask option for outgoing calls so you can select a SIM card before each call.
• 📊 Traffic monitoring: Use the built-in traffic counter in the MIUI (Settings → SIM cards. → Data traffic) to control internet consumption on each SIM card.

If you switch between SIM cards frequently, create shortcuts on the home screen:

1. Keep an empty space on the main screen → Widgets.
2. Find the switch widget. SIM or mobile data.
3. Add it to the screen for quick access.

For advanced users, there is an opportunity to customize DUO through the engineering menu (but it requires caution):

Enter the phone app: ##4636##


Go to the section "Phone Information"




Select the desired SIM card and check the network settings

Beware: Incorrect changes to the engineering menu can lead to failures!

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In the models with MIUI 13 and newer in settings DUO Smart Switching – it automatically selects the SIM card with the best signal for calls and the Internet.

FAQ: Frequent questions about DUO Xiaomi Redmi