Two. SIM-Cards in one smartphone are not a luxury, but a necessity for many users: business and personal calls on different numbers, favorable rates from two operators or travel from the local SIM — Reasons to Use Dual SIM Xiaomi smartphones (including the Redmi line and POCO) This feature has been supported for a long time, but not all users know how to configure it correctly.
In this article, you will find step-by-step instructions for activating the second line, tips for choosing a priority SIM for calls and mobile Internet, as well as solving typical problems from lack of network to conflicts between cards. We will look at the features of setting up MIUI 12/13/14 and new versions of the HyperOS shell, and also give recommendations for older models (for example, the Redmi Note 4X or Mi A1).
If you just bought a Xiaomi smartphone with dual SIM support or have been using it for a long time, but have never tried the second line – this guide will help you avoid mistakes and save time.
Check the support of Dual SIM with your Xiaomi model
Before you try to turn on a second SIM, make sure your smartphone physically supports two cards.Even if there are two slots in the tray, this does not guarantee full Dual SIM operation.
Here’s how to check compatibility:
- 🔍 Official website: Find your model on mi.com and check the specifications under "Network & Connectivity." SIM (Nano-SIM, dual stand-by).
- 📄 Documentation: The box or instructions to the phone usually indicate the number of supported SIM. For POCO X3 Pro, Redmi Note 12 or Xiaomi 13T It's always two nano-SIMs.
- 🛠️ Visual inspection: Remove the tray for SIM-If there are two separate slots under the nano-SIM (or one combined under the SIM + microSD, so it's supported. Except for hybrid slots (SIM + microSD, where the second SIM Replace the memory card, so only one will work at the same time. SIM microSD.
| Xiaomi model | Dual SIM Support Type | Notes |
|---|---|---|
| Redmi Note 10/11/12 | Dual Nano-SIM + MicroSD (Hybrid) | Second SIM or MicroSD to choose from |
| POCO F4/F5 | Dual Nano-SIM (without microSD) | Full support for two SIMs |
| Xiaomi 13/14 | Dual Nano-SIM + eSIM | Support for physical and virtual SIM |
| Redmi 9A/9C | Dual Nano-SIM + MicroSD (Hybrid) | Budget models with limitations |
⚠️ Note: Some models (e.g. Xiaomi Mi 11 Ultra) have a second model. SIM It can only work in the mode 2G, if the first use is 5G. This is a hardware limitation - check the specifications!
Preparing your phone: What to do before installing a second SIM
To avoid setup problems, follow a few simple steps before installing the second one. SIM-map:
- Update your firmware. Go to Settings → About Phone → Update your system and install the latest version of MIUI or HyperOS. This will eliminate possible bugs with Dual SIM.
- Back up. Go to Settings → Additional → Backup and Reset and save your data. If you crash, you can quickly restore contacts and SMS.
- Check the tray for SIM. Make sure the sealing rubbers on the tray are intact - they protect against dust and moisture. If the tray is bent, replace it (stands). ~200₽).
If you use a hybrid slot (SIM + microSD), decide which is more important: a second line or additional memory. For example, on the Redmi Note 8 Pro you can not use two SIM and microSD at the same time, you have to choose.
Also note that some carriers (such as Tele2 or Yota) may block the second SIM from another provider, which is due to network settings, which are rare but possible.
Step-by-step: how to turn on the second SIM on Xiaomi
Now, the main thing is activation of the second line. The instructions are suitable for all modern Xiaomi smartphones on MIUI 12-14 and HyperOS. If you have an old model (for example, Redmi 4X), some menu items may differ, but the logic remains the same.
☑️ Preparation for activation of the second SIM
- Set up the second. SIM-Map: Turn off the phone. Remove the tray for SIM Place the second nano-SIM in the free slot (if the slot is hybrid, choose priority: SIM Or microSD. Put the tray back in before you click.
- Turn on the phone and wait for recognition: After downloading, the icon of the second will appear in the status bar SIM (usually with the number "2" or operator name. If the icon is not, go to Settings → SIM-maps and mobile networks.
- Activate the second. SIM: Settings → SIM-maps and mobile networks → [Title number two SIM] → Enable if the system requests PIN-Enter the code (usually listed on the plastic holder) SIM or in documents from the operator).
- Select your priorities: In the same menu, select which one SIM will be used by default for: 📞 Calls. 💬 SMS 🌐 Mobile Internet, for example, can be used for the first time. SIM The main one is for calls, and the second one is for the Internet.
If the second SIM does not catch the network after activation, try to manually select the operator:
Settings → SIM- Maps and Mobile Networks → [SIM 2 → Network Selection → ManualSometimes, automatic search loops in and manual selection solves the problem.
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If the second SIM is not detected, try restarting the phone or swapping the cards. Sometimes the tray contacts oxidize - wipe them with a wipe.
Set up calls and internet for two SIMs: what you need to know
After activating the second line, it is important to correctly distribute the load between the two. SIM-Here are the key points:
- 📶 Mobile Internet: By default, the Internet works only through one SIM. To switch, go to Settings. → SIM-maps and mobile networks → Mobile Internet and choose the right one SIM. Please note that if one SIM use 4G/5G, second — 2G, Internet speed will be limited by a slow network.
- 🔄 Switching during a call: On Xiaomi you can choose from which SIM You can call right when you dial. SIM near-button.
- 📵 Regime “Only” 2G": If the second SIM catcherless 4G, Check if the compulsory regime is included 2G network-setting.
Pay special attention to configuring call forwarding. If one SIM is not available (for example, roaming), calls can be redirected to the second:
→ SIM-maps and mobile networks → [SIM 1] → Call forwarding⚠️ Note: Some Xiaomi models (e.g. Redmi 7) are active on one SIM The second one is temporarily disconnected, which is normal behavior for dual stand-by phones).
If you travel frequently, set up roaming in advance:
Settings → SIM- Maps and Mobile Networks → [SIM] → Roaming → IncludeSome operators (such as MTS or Beeline) automatically activate roaming, but it is better to check manually.
Problem Solving: Second SIM is not working or catching the network
Even when set up correctly, the second SIM can be unstable, and here are the most common problems and solutions.
| Problem. | Possible cause | Decision |
|---|---|---|
| SIM is not defined | Bad contact at the slot | Remove and insert the SIM again, wipe the contacts with a lastic |
| No network on the second SIM | Wrong APN settings | Reset network settings: Settings → SIM-map → Resetting network settings |
| The Internet only works on one SIM. | Limitation of operator | Check the fare – some operators block the Internet on the second SIM |
| SIM only works with 2G | Limitation of the phone model | Check the specs – some Xiaomis don’t support 4G on the second SIM |
If the second SIM is detected but does not catch the network, try:
- Manually select the operator (as described above).
- Reset network settings: Settings → System → Settings Reset → Reset settings Wi-Fi, mobile network and Bluetooth.
- Check if the flight mode is turned on for the second SIM (occasionally when there are failures).
- Update the operator profile: Settings → SIM-maps and mobile networks → [SIM 2] → Update profile
If nothing helps, check it out. SIM-The card is on another phone, and it may be the card itself (for example, it is damaged or blocked by the operator).
What if the second SIM only works in 2G?
Features of Dual SIM on the new Xiaomi with HyperOS
In 2026, Xiaomi began the transition to a new HyperOS shell, which replaced MIUI, which changed the Dual SIM settings interface, but the logic remained the same.
- 🔄 Quick switching: The notification bar now displays both SIM With the ability to instantly switch mobile Internet (click on the network icon) → choose SIM).
- 📊 Traffic statistics: In Settings → Mobile network has a section with detailed traffic statistics for each SIM separately.
- 🔒 Improved security: You can now install a separate PIN-code SIM (before he was common).
HyperOS also has a Smart Switch feature, where the phone automatically selects the SIM with the best signal to call, to turn it on:
Settings → Mobile Network → Smart SIM Switch → EnableNote: On some models (e.g. Xiaomi 14), HyperOS supports eSIM.
- Get it. QR-activation code or data from the operator.
- Go to Settings. → SIM-maps and mobile networks → Add eSIM.
- Scan the QR or enter the data manually.
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On HyperOS, the second SIM can run in the background even when the first one is active — this is called Dual VoLTE. But the feature is not available on all models (check the specs).
How to turn off the second SIM without removing it from your phone
If you don't need a second line temporarily (for example, when traveling abroad), you can turn it off without physically removing it, which is convenient if the tray is difficult to reach or you are afraid of damaging the seals.
Here's how to do it:
- Open the Settings. → SIM-maps and mobile networks.
- Select the second SIM (it will be marked as SIM 2 or operator name).
- Translate the slider Include in the position Off.
- Confirm the action if the system requests PIN-code.
After the shutdown:
- 📵 Calls and SMS this SIM They won't come.
- 🌐 Mobile Internet (if configured to it) will automatically switch to the first one. SIM.
- 🔄 To activate again SIM, Repeat the same steps and turn on the slider.
If you plan to not use the second SIM for a long time (for example, more than a month), it is better to physically remove it, even when it is turned off, it consumes a small battery charge to scan the network.