Modern smartphones like the Xiaomi Redmi 8 allow users to manage two or more phone numbers at the same time, making it much easier to separate personal and work contacts. SIM-The system does not always automatically select the preferred option for various actions. the user often has to manually adjust priorities to avoid overpaying for roaming or spending traffic from inappropriate rates.
Android’s MIUI-enabled operating system offers a flexible SIM management mechanism that gives you complete control over which chip to use for outbound calls, messages or mobile Internet connections. Incorrect configurations can lead to unexpected costs, especially if one card doesn’t have an unlimited data packet or minutes are running out. In this article, we’ll detail the default card assignment process.
By understanding the intricacies of the setting, you can optimize the operation of your gadget and avoid unnecessary costs. SIM-Each type of card is individually or forcefully asked for a choice at each action, which provides maximum flexibility in using the mobile device in any life situation.
Control interface SIM-card MIUI
Shell MIUI, And the one that's installed on Redmi 8, it offers a centralized control point for all connections, and to get into it, you have to open Settings and find the partition that's responsible for wireless networks. SIM-maps and mobile networks. That's where all the key switches are concentrated.
In this menu, the user sees a visual display of both cards installed, their current status and signal level. The interface is intuitive: each card has its own color indicator, which will later be used in the system to indicate the selected communication source, which helps to quickly navigate, especially when you need to make an urgent call.
⚠️ Note: If you take one of the SIM-the card settings will automatically reset, and when re-installed, the system may require you to re-state your priorities for use.
It is important to note that depending on the version of the MIUI firmware (Global, China or Russia), the item names may vary slightly, but the logic of the operation remains the same. Access to these settings does not require superuser rights or complex manipulations, all changes are applied instantly.
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Use the "Name" function. SIM-cards" to rename them "Worker" and "Personal" - this will help not to get confused when choosing a number for a call.
Choosing a card for mobile Internet
The most important option that requires the attention of the owner of Xiaomi Redmi 8 is the assignment of the card to transfer data. Mobile Internet is consumed by background processes constantly, so an error in selection can quickly empty the balance.
You are asked to choose one of the available SIM-Once the selection is confirmed, this channel will be used to send all the traffic to the applications, if they are not connected to Wi-Fi. The system will automatically forward the requests to the selected communication module, even if the conversation is on a different line.
The Redmi 8, as with many budget models, may have a 4G network restriction. Often only one card can run in LTE mode, while the second card will be forced to switch to 2G or 3G mode to provide voice communication.
- 📱 Choose the card with the most traffic pack for cost savings.
- 🚀 Make sure that support is included on the selected card. 4G/LTE customized.
- 🔄 When switching the Internet may be a short-term break in the connection.
- 📶 Check the signal level at your permanent location for the selected operator.
Setting priorities for calls and SMS
Beyond the Internet, it's critical to adjust the behavior of your smartphone when making outgoing calls. You can set the default card in the Voice Menu (or similar), but MIUI offers a more flexible scenario — ask. If you choose this option, each time you dial, the system will display a pop-up with a suggestion to choose a SIM card.
For messages, the situation is similar: you can assign a primary card to SMS or leave the choice to yourself. The usability depends on your habits: if you rarely call from the second SIM, it is easier to assign one main card so as not to be distracted by the choice.
Some firmware versions have a Smart Calls feature that tries to analyze which card you call a particular contact from and offers it first, which can be useful but sometimes doesn't work properly, so many users prefer static settings.
⚠️ Note: When activating roaming, make sure that the local operator card is not selected for calls and the Internet, unless you have a special tariff connected, otherwise the bill can be huge.
☑️ Checking the communication settings
The “Always Ask” Mode and Its Features
One of the most useful features in the Xiaomi Redmi 8 is the ability to delegate the decision to the system at the moment of action, and the option “Ask every time” eliminates the need to constantly climb into the settings if you periodically change preferences.
When this mode is activated, when you try to make a call, a dialog box will appear on the screen, which will display both SIM cards indicating the current balance or the remaining minutes (if the operator supports the transfer of this information), which prevents accidental calls from a number that does not have money.
But there's a downside to this, too: If you need to make a series of calls quickly, the constant appearance of the selection window can be annoying and slowing down the process, and some call apps may not handle that request properly, causing a connection delay.
| Parameter | Fixed SIM | Always ask |
|---|---|---|
| Rate of recruitment | Instant. | Delay in choosing |
| Risk of error | Medium (forgot to switch) | Low (manual selection) |
| Convenience | High for permanent rooms | High for variable needs |
| Battery consumption | Standard. | Slightly higher (screen activity) |
What happens if the window of choice does not appear?
Problems with network and 4G definition
Redmi 8 owners may experience a situation where the Internet is down or slow after setting up, often because the SIM 2 slot is not running fast, or the APN settings are down, and checking the APN settings is the first step in diagnosing.
Also, it is worth considering that when you actively talk on one SIM card, the second can temporarily lose the network or switch to Unavailable mode if the smartphone does not support VoLTE technology on both numbers at the same time.
If the Internet goes missing after a call, try using your mobile network settings to find the preferred network type and switch it from LTE to 3G/2G and back again, which will restart the communication module and re-register the device in the operator’s network.
- 🔍 Check if the service is active 4G your operator.
- ⚙️ Reset the access point settings (APN) factory-to-factory.
- 📡 Make sure that the region has coverage of the selected communication standard.
- 🔄 Reboot the device after the change SIM-map.
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Stability 4G-The connection depends on the correct setting of the access point (APN) Support for the VoLTE standard by your operator.
Additional functions of managing two numbers
The MIUI shell offers a number of support tools for dual SIM card users, such as Call Limitation, which allows you to block outgoing calls from a particular SIM, which is useful for parental control or locking work numbers on weekends.
You can also customize different notification sounds and ringtones for each SIM card, so you can hear the number you're calling without taking your phone out of your pocket, and you can set it up in the Sounds and Vibrations section.
Remember that using two active SIM cards can increase the battery consumption of Redmi 8. Finding a network and maintaining registration on two different networks requires energy. Optimizing the background processes will help to extend battery life.
⚠️ Note: Do not use hand-cutting SIM-Redmi 8 slots cards, as they can get stuck or damage contacts inside the tray due to the slightest sizing error.