Owners of modern smartphones Xiaomi, Redmi and Poco often face the need to manage two numbers at the same time, this can be the separation of personal and work contacts or use different tariff plans to save on calls. However, the standard interface of the shell MIUI or HyperOS is not always intuitive for beginners, especially when you need to urgently make an outgoing call from the number that is not selected by the main one.
The problem of choosing a SIM card is relevant, because a random call from the wrong number can lead to unnecessary costs or awkward situations. In this article, we will discuss in detail all ways to manage outgoing calls, you will learn to adjust persistent preferences, use quick switches and apply special codes to force the selection of the network.
We're going to look at not only the standard methods, but also the hidden features of the system that allow you to manage communications flexibly, and understanding these settings will help you avoid confusion and always be connected from the right number. Let's go from theory to practice and set up your smartphone correctly.
Basic preferences for calls to MIUI
The first thing you need to do to make two SIM cards more comfortable is to adjust your system’s global preferences. The MIUI shell allows you to set one SIM card as the default for voice communication, which means that when dialing from contacts or call history, the system will automatically use the selected module.
To change these settings, you need to go to the settings menu. → SIM-Maps and mobile networks. This is where you see both maps installed, with their names and operators, and this is where the primary configuration of communication priorities takes place.
At the top of the screen, you'll see "Default for Calls." Clicking on it will suggest three options: always use SIM 1, always use SIM 2, or ask every time. The latter option is the safest if you change your tariff plans often or are afraid to spend minutes on the wrong account.
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Choosing the “Always Ask” option when calling eliminates incidental costs, but requires additional action with each dial.
It is worth noting that the settings may vary slightly depending on the Android version and regional firmware. In some cases, the menu item may be called "Preferred". SIM-It is important to carefully study the available options so as not to get confused in the future.
How to choose a SIM card immediately before a call
If you haven’t set a hard priority or want to make a one-time call from a “second” number, the smartphone interface provides handy tools for quick switching.Standard dialing in Xiaomi comes with visual indicators that let you choose a SIM card in one click.
Open the Phone app and dial the number you want or find a contact in the list. Before you press the green phone, look for the area under the dialed number or next to the call button, which usually displays an icon of the current selected SIM card with the number "1" or "2".
Click on this icon or operator name, and you'll see a small pop-up window where you can instantly switch to another SIM card, and then you'll see the right number in the right color, and then you'll press the call button, and this action doesn't change the global settings, it's only valid for the current session.
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When dialing a number manually, pay attention to the color of the call button – green often means SIM 1, and blue or another color is SIM 2, depending on the theme of the design.
In some versions of the shell, the switch can be directly above the digital keyboard, which is especially convenient if you type by hand rather than from contacts, and the system remembers the last choice for a particular contact, which makes it easier to repeat calls.
Use of codes and prefixes for forced selection
For power users who prefer keyboard input or use headsets without touch control, there are special codes that allow you to force the system to specify which channel to connect through, and this is especially true when automatic settings fail or the interface is not available.
In mobile, the standard is to use prefixes before the phone number. To call from the second SIM card, you need to enter a special character before the subscriber number. In most cases, the first SIM uses code 1, and the second one uses 2. However, Xiaomi smartphones often use the format with a grille.
Try dialing the following combination before the main number: 2 or #2#. For example, if the subscriber number is 79990000000, dial *2*79990000000 to call from the second SIM and press the call. The system recognizes the prefix and directs the call through the desired communication module, ignoring the standard default settings.
Why can codes not work?
If standard combinations don’t work, check your operator’s documentation or try alternatives, such as adding a suffix after a number.
Set up activities for different contacts
Managing two numbers is much easier when you set up customized rules for specific contacts, and the MIUI shell allows you to link a particular SIM card to a specific person in the phone book, eliminating the need to check which number you're calling from each time.
To implement this feature, open the Contacts app and select the subscriber card you want. In the contact editing menu (usually a Change button or a pencil in the corner), find the field responsible for the SIM card «SIM-Default card" or have a SIM card icon next to your phone number.
Once you save the changes, all outgoing calls to that subscriber will be automatically made via the selected SIM card, a very useful feature for separating work and personal contacts, allowing you to keep your finances in order.
- 📞 Open the contact card in the phone book.
- ✏️ Press the edit button (usually in the upper right corner).
- 📱 Find a SIM card icon or item «SIM-default-card».
- ✅ Select the desired number and save the changes.
It is worth considering that if you reset your phone settings or move contacts through SIM-This is why it is recommended to back up contacts to your Google account or Xiaomi cloud.
Solving problems with the definition of the second SIM card
Sometimes users are faced with a situation where the second SIM card is no longer defined or is not available for outgoing calls, this can be caused by a software failure, improper installation of the tray or problems with network settings, in which case step-by-step diagnostics are required.
First, check the physical condition of the SIM card. Remove the tray and make sure the chips are not damaged and the card sits tightly in the slot. Xiaomi's two-sym trays often use a combined slot where improperly installing the card can lead to a lack of signal.
If everything is physically okay, go to the Settings menu. → SIM-Maps and mobile networks. Make sure the second SIM card activation slider is on. Sometimes, after the system update, the settings may get lost, and the card goes into Data Only mode or completely shuts down.
☑️ Diagnostics of problems with the second simka
It is also worth checking whether there is a Do Not Disturb mode or a restriction on the second SIM card, which in some cases helps switching network mode from 5G/LTE to 3G and back, which forces the module to re-register in the operator’s network.
Comparison of call management methods
To make it easier for you to navigate your call management, we've developed a spreadsheet that will help you quickly determine which method is best for your situation.
| Method | Speed of access | Flexibility | Risk of error |
|---|---|---|---|
| Global tuning | Tall. | Low. | Medium. |
| Choices when calling | Medium | Tall. | Low. |
| Prefix codes | Low. | Medium | High-pitched |
| Contact binding | Tall. | Medium | Low. |
As you can see from the table, there is no perfect method for all cases, and combining these approaches yields the best result, for example, you can set a global priority for the main SIM, and for important work contacts, customize the individual binding.
⚠️ Note: When using prefix codes, carefully check the dialed number before calling, so as not to make a call to the wrong number or write off money from the international roaming account if the prefix is interpreted incorrectly.
Frequent Questions and Answers (FAQ)
Can you make your phone ask for a SIM card only for certain contacts?
Why doesn’t the second SIM card offer a choice when calling?
Will the SIM card be selected after the system update?
Do SIM card selection codes work in messengers?
⚠️ Note: If you use a corporate SIM card, make sure your choices don’t conflict with your company’s security policies, especially when using third-party call management apps.
Competent management of two SIM cards on Xiaomi is a skill that makes life much easier. Using these methods, you can fully control your communications, avoiding unnecessary costs and confusion. Don't be afraid to experiment with settings to find the perfect balance for your communication style.