Xiaomi’s modern smartphones support two SIM-With cards that allow you to separate personal and work numbers, enjoy the best rates of different operators or keep in touch with roaming, however, many owners face difficulties in the first setup of the second line: It doesn't see the map, it doesn't save priority settings, or it loses the mobile Internet. In this article, we'll look at all the steps, from the physical setup to fine-tuning the network settings, including solving typical problems.
The configuration of the second SIM on Xiaomi depends on the device model: hybrid slots (where the second slot is combined with a memory card) require a choice between memory expansion and the second line, and the flagship models of recent years (for example, Xiaomi 13 Ultra or Redmi Note 12 Pro+) support full-fledged two nano-SIMs without compromise. We will consider both options, and also explain how to correctly distribute traffic between cards and avoid conflicts when calling.
Before you start setting up, make sure that your smartphone supports Dual SIM. Check this in the characteristics of the model on the official Xiaomi website or in the Settings menu → About the phone → SIM Characteristics. If it specifies Dual SIM Dual Standby (DSDS), then the device is ready to work with two cards at the same time.
Important: some operators (such as Tele2 or Yota) may block the second SIM in certain regions, and if the card is not determined after installation, contact the operator and check whether roaming between SIMs is supported in your tariff.
1. Physical installation second SIM-map
The first step is to insert the second card correctly into the slot.Most modern Xiaomi are equipped with a hybrid tray, where the second slot can be used either for nano-SIM or for microSD. The exception is the flagship models (Mi 11/12/13, Redmi K50), where both slots are designed only for SIM.
To remove the tray, you'll need a paper clip or a special key (complete with your phone) insert it into the hole on the sidebar before you click, the tray will move out automatically. Don't use needles or sharp objects: this can damage the mechanism.
What if the tray is jammed?
Set the cards according to the scheme on the tray:
- 📱 SIM 1 — The main slot (usually supports) 4G/5G).
- 📱 SIM 2 - Second slot (may limit speed to up to a maximum) 3G old-model).
- 💾 MicroSD – only if the second one is not used SIM (hybrid-slot).
After installation, turn on your phone and wait for the network to be identified. If one of the cards doesn't recognize, check:
- Correct installation (the card should fit tightly to the contacts).
- Chip integrity (no scratches or chips).
- Support your operator’s frequencies (for example, MTS and Beeline in Russia use B1/B3/B7/B20 for 4G).
2. Activation of the second SIM in the settings
After the physical installation, you need to turn on the second line in the settings menu.
- Go to Settings. → SIM-maps and mobile networks.
- Slip on the second SIM (it can be displayed as SIM 2 or Slot 2).
- Activate the switch Turn on SIM-map.
If the option is inactive, check:
- ⚠️ Card type: Some Xiaomi does not support eSIM in the second slot (physical only) SIM).
- ⚠️ Firmware Region: on Global Versions (Global) ROM) There may be no support for Dual. SIM for certain operators.
On models with MIUI 14 and later, there is a smart switching function called SIM (Smart SIM Switch), which automatically selects a card for calls based on the tariff.
Settings → SIM- Maps and Mobile Networks → Smart Switching SIM → Include3. Priority setting of the network and the Internet
By default, Xiaomi prioritizes mobile data with the first SIM. To change this,
- Go to Settings → SIM-cards and mobile networks → Mobile Internet.
- Select SIM 2 in the Use for Mobile Data section.
- Activate Enable 4G/5G (if supported by the operator).
To save traffic, you can configure separate data use:
- 🌐 Basic SIM — internet-based.
- 📞 Second second SIM — call-only/SMS.
On models with MIUI 13+, Dual 4G is available, allowing both SIMs to work on a 4G network simultaneously (previously the second card was limited to 2G/3G).
Settings → SIM- Maps and Mobile Networks → Additional → Include Dual 4G💡
If the connection disappears after the Dual 4G is turned on, check if your operator supports this feature, for example, in Russia it is officially supported by MTS and Beeline, and MegaFon only at separate tariffs.
4. Call management and SMS
By default, all outgoing calls and SMS are sent with the main SIM. To change this:
- Open the Phone app.
- Press three points (⋮) → Settings → Calls. → SIM outgoing.
- Choose Always Ask or choose your preferred SIM.
For SMS, the setting is similar:
Messages → ⋮ → Settings → SIM to send SMSOn models with MIUI 14, we have the automatic SIM selection feature for contacts, for example, if you often call a number with one SIM, the system will offer it by default.
Settings → SIM- Maps and Mobile Networks → Automatic Selection SIM → IncludeInstall SIM default|Set up automatic selection SIM|Check the balance on both cards|Test call for every one SIM-->
5. Solving typical problems
If the second SIM does not work, use this table to diagnose:
| Problem. | Possible cause | Decision |
|---|---|---|
| SIM is not defined | Incorrect installation, damaged map | Reinstall the card, check on another device |
| There's no mobile Internet. | Infidels APN-setting | Reset APN to Settings → Mobile Network → Access Points (APN) |
| Calls are breaking down. | The Dual SIM Conflict | Disable Dual 4G or change SIM priority |
| 5G is not working | Limitation of operator | Check 5G support on the operator’s website |
If the problem persists, reset your network settings:
Settings → SIM-cards and mobile networks → Resetting mobile network settings⚠️ Note: On some models (Redmi) 9A, Poco M3) discharge APN It may cause you to lose your settings. MMS. After resetting manually add APN your operator (options can be found on its website).
6. Optimization of the two SIMs
To ensure that both SIMs work in a stable manner:
- 🔋 Turn off automatic network switching in roaming (saves charge).
- 📶 Set your priorities 4G/5G basic SIM, If the second is used only for calls.
- 🔄 Reboot your phone regularly (every 2-3 days) to reset possible communication module conflicts.
For advanced users: MIUI has a hidden SIM test menu (#4636##) where you can check the signal strength of each card and force the network type to switch. Don't change the settings in this menu unnecessarily - this can disrupt the communication module.
💡
On Qualcomm Snapdragon models (e.g. Xiaomi 12T or Poco F4), the Dual SIM is more stable than on MediaTek processors (e.g. Redmi Note 11), where network switching problems are possible.
7. Features for different Xiaomi models
The settings of the second SIM may vary depending on the series of devices:
- 📱 Flagships (Mi) 11/12/13, Mix 4): Supporting Dual 5G (both SIM They can work on the network. 5G simultaneously).
Xiaomi has a virtual second SIM (Dual SIM Dual Active) feature with HyperOS (2026), which allows you to use one physical SIM and eSIM simultaneously, to activate it:
→ SIM-maps and mobile networks → Add eSIM⚠️ Attention: Virtual SIM (eSIM) on Xiaomi is supported only on models with Snapdragon 8 Gen 2 processor and later (for example, Xiaomi 13 Pro or Redmi). K60 On other devices, the option will be inactive.