Owning a smartphone from Xiaomi opens up wide opportunities for the user to manage mobile communications, which is especially important in today's realities, when one gadget often performs the functions of a working and personal device. Many owners face the need to quickly change priorities for incoming calls or mobile traffic, not wanting to physically remove the tray every time. Switching these cards at the software level allows you to flexibly configure network use scenarios, saving battery power and cost to pay tariffs.
MIUI and the new HyperOS shell offer advanced tools to manage two or more communication profiles, but standard settings are sometimes hidden in non-obvious menus. Understanding the logic of communication modules will help avoid situations where the Internet suddenly disappears during a conversation or SMS leaves the wrong number from which it was planned.
It's worth noting that the right configuration prevents random roaming costs and provides a stable signal in areas of uncertain reception. It's critical to properly configure the APN when changing your priority SIM card for the Internet, because automatic settings may not apply instantly. Let's look at how to effectively manage this process.
Basic management settings SIM-map
To start with two numbers, you need to make sure that both cards are correctly defined by the system and activated. → SIM-maps and mobile networks, where the status of each of them is displayed, and here the user sees the basic information about the balance, if the operator supports the technology. USSD-requests and current network operation.
In this section, you can set the primary SIM card for voice calls and separately for data transfer. The priority SIM card for the Internet will be used by all applications by default, if they do not have their own internal network settings, this allows you to keep the tariff with unlimited traffic active for navigation and streaming while the second number receives important work calls.
The interface of settings may vary slightly depending on the firmware version, but key switches remain in place. The system allows not only select actions, but also to adjust the behavior of the smartphone when making an outgoing call.
If one of the cards is rarely used, such as only receiving SMS from the bank, it can be temporarily disabled software to avoid wasting battery life searching the network, just switch the corresponding switch to the "Off" position in the same settings menu, which is especially useful in places with a very weak signal, where the phone is constantly trying to keep in touch with the tower.
Setting priorities for calls and the internet
Xiaomi’s Android flexibility allows you to create complex communication scenarios. You can set up a constant selection of SIM cards for outgoing calls or have your phone ask you every time. → SIM-maps and mobile networks → Challenges.
There are three basic modes of behavior available here:
- 📞 Always use SIM 1 – calls will only go through the first operator, the second number is ignored for outgoing communication.
- 💬 Always use SIM 2 – similar mode, but priority is given to the second card.
- ❓ Always ask – when dialing a number, the selection window pops up, which is convenient for rare calls from the second number.
The same logic applies to mobile Internet settings, where you select the map that the traffic will go through.
☑️ Verification of priority settings
For users who change terms of use frequently, there is a Smart Switch feature that allows you to automatically change the SIM card to call if the main card is not on the network or it is busy, but this feature requires careful adjustment so that you do not make a call at a more expensive rate accidentally.
Dual SIM and 4G/5G
One of the key features of modern Xiaomi smartphones is the support of technology that allows both numbers to be in the networks of the fourth and fifth generation at the same time. 2G/3G, So, what made it impossible to receive VoLTE calls? → SIM-Maps and mobile networks can be activated in the "Use" mode. 4G/5G second SIM-map».
The inclusion of this option provides high quality communication on both numbers, but has its own technical nuances. When two 4G/5G networks are active, there may be slightly increased power consumption, since the radio module operates in a more intensive mode. In addition, not all operators and tariff plans support VoLTE technology, so you should check this information with the provider before turning on.
If you notice that after turning on this feature, the Internet speed has decreased or the connection has become unstable, try to switch the preferred network type. You can do this by clicking on the operator name in the SIM card settings menu and selecting the Preferred network type.
What is VoLTE and why is it needed?
It is worth considering that when using two active 4G/5G networks in some regions, you can experience faster battery discharge. If you are in the zone of confident reception, but autonomy for you is more important than speed on the second number, you can leave the second SIM card in 3G mode.
Switching SIM cards during calls and in contacts
Often, you have to make an urgent call from an additional number rather than the main one, without changing the global settings of the system. Xiaomi provides a convenient switching mechanism directly in the dialing interface. When you enter a number or open a contact card, pay attention to the call button.
If you have a "Always Ask" setting in the global settings, clicking on the green handset will show a SIM selection menu, however, if you have a fixed choice (e.g., always SIM 1) but need to call with SIM 2, do this:
- 📱 Click on the SIM card icon next to the call button – it will change to another.
- 🔄 Or press and hold the call button – the selection menu will open.
- 👆 In some versions MIUI You just need to tap the operator name over the digital keyboard before dialing.
It's also convenient to set up a SIM card for specific contacts. Open the Contacts app, select the person you want, and click Change. The default SIM card option for that contact often appears at the bottom of the screen. By choosing the right number, you'll save yourself from having to remember who you usually call from which card.
| Action. | Switching method | Where applicable |
|---|---|---|
| Global shift | Settings → SIM-map | For all future calls |
| One-time call. | Selection button in dialing | Only for the current challenge. |
| Continuous contact | Editing of the contact card | For calls to a specific person |
| The Internet's change | Notifications curtain / Settings | For all data traffic |
Using a personalized setup for contacts makes life much easier for those who share personal and work communication: The phone will itself offer the desired number when you decide to contact a colleague or loved one.
Control through notification curtain and widgets
To get the most out of mobile data switching between SIM cards, you don't have to go through the deep settings menus every time. MIUI and HyperOS have a handy widget in the notification curtain. Swipe from top to bottom to open the control center, and find the mobile network icon.
It usually looks like two up-and-down arrows or an antenna icon. If you click on it, you can open a mini menu where you can quickly choose which SIM card to use for the Internet. In some design themes, this element can be hidden, then you need to add it through the edit button (usually a pencil or three dots in the corner of the curtain).
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Add the Data Use widget to your desktop to see traffic consumption from each SIM card separately and respond quickly if limits are coming to an end.
There are also third-party widgets from the operator or system security widgets that allow you to manage SIM cards. However, you should be careful with widgets from unknown developers, as they may request excessive permissions. Standard system tools are usually quite enough for comfortable use.
⚠️ Warning: If you quickly switch your SIM card in the curtain, the active connection (file download, video calls) will be interrupted.
If you often forget which card is currently active for the Internet, turn on the network icons in the status bar. In the Notifications and Status bar settings → The status bar icons make sure that the displays for both SIM cards are turned on. This will allow you to determine the current status of the connection with one glance.
Solving switching and stability issues
Despite the cleverness of the system, users may encounter situations where switching does not work or the Internet does not appear after a priority change. Often the problem lies in the wrong settings of the APN access point. When changing the main SIM card for data, the smartphone must automatically load the settings, but sometimes this process fails.
If the Internet does not work after switching, follow the following steps:
- Go to Settings. → SIM-maps and mobile networks.
- Choose a SIM card that works with the Internet.
- Press Access Point Names (APNs).
- Press the reset button (usually at the bottom or in the menu) or create a new point manually by taking data from the operator's website.
Another common cause of problems is the outdated software of the radio module. Check for system updates in the About Phone menu. Also helps to simply restart the device after changing the network settings, which allows you to reset temporary login errors in the operator's network.
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If the Internet does not work after switching SIM cards, in 90% of cases, resetting APN settings to factory values in the menu of the selected SIM card helps.
In rare cases, conflict can arise from physical damage to the tray or the SIM cards themselves (for example, if they are cut by hand). Make sure the cards sit tightly in the slot and the contacts are clean. If the problem persists on different SIM cards of different operators, you may need to diagnose the hardware of the smartphone in the service center.