Owning a smartphone with two active SIM cards has long been a rarity and has become a standard for many users, especially in the Xiaomi ecosystem. The ability to separate personal and work contacts, as well as use different tariff plans for calls and mobile Internet, greatly simplifies life. However, when you first get acquainted with the shell of MIUI or the new HyperOS, owners often wonder how to manage outgoing calls from a particular SIM card, so as not to spend money from the main account or not to glow with the work number after hours.
The Android system installed on Redmi and Poco devices provides flexible tools for managing dual communication, but they are not always obvious at first glance. The dialing interface can be confusing for beginners, since the SIM control buttons can be located in different places depending on the firmware version. Understanding the logic of the standard call and system settings will allow you to avoid random costs and always be sure what number the subscriber will see at the other end of the wire.
In this article, we will take a look at all the ways that you can make calls, from manual selection before each set to automatic rules for different contact groups, and we will touch on the nuances of working with operator codes that allow you to temporarily switch priority, and also look at the typical errors that prevent the correct operation of the second line, competently adjusting these parameters will make your smartphone an ideal tool for communication.
Basic Call Priority settings in the system
The first thing that a user faces after installing a SIM card is to determine which one will be used by default. In Xiaomi devices, this is a special section in the settings that globally changes the behavior of the phone when outgoing calls, unless you manually selected the number immediately before dialing, which is a fundamental setting that you need to check first.
To access these options, you need to go to the Settings menu and find SIM cards and mobile networks. This is where the Calls key switch is, where you can hard-fix one of the SIM cards as your primary voice card. If you set Sim 1 here, when dialing from contacts or call history, the phone will always try to use the first card, ignoring the second one, unless you specifically change this choice at the time of the call.
⚠️ Warning: Setting a constant priority for a single SIM card can lead to an unexpected expense if you forget to call from a number that ran out of free minutes.Always check the active SIM card before an important conversation.
But it allows you not only to lock one card, but also to ask a question every time you call, and if you choose Always Ask, the dialing interface will change, so you'll have a pop-up or an extra select button before you connect, which is the safest option for those who are actively using both numbers throughout the day and are afraid to confuse them.
Manual selection of SIM card in the dialing interface
Even if global settings prioritize one SIM card, the MIUI dialing interface makes it easy to change that decision on the fly, the fastest way to call from a second SIM card without digging into the depths of the settings menu. The visual design of this feature may vary slightly depending on the theme, but the logic remains the same for all models.
When you open the Phone app and dial a number, look at the area below the numbers or next to the call button. There are usually two small icons with operator logos or labels 1 and 2. Clicking on one instantly changes the active SIM card for the current dial. If you just called from the first card, but need to make an outgoing one from the second, just tap the corresponding icon before pressing the green handset.
In some versions of the shell, especially in horizontal mode or on Xiaomi Pad tablets, select buttons can be displayed in a separate panel. It is also worth noting the dual tap function: in some cases, re-pressing the call button can cyclically switch SIM cards, although this gesture depends on the specific availability settings.
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If you often forget to switch SIM cards manually, try assigning different colors to the call buttons of each SIM card in the design themes settings – this will help visually control the choice.
Once the conversation is over, the system will return to the default priority you set in the basic settings, which means you will have to switch again if you plan to make a series of calls from the second card.
Use of switching codes and prefixes
For advanced users who prefer speed and accuracy, there are special codes and prefixes that allow you to control the selection of a SIM card directly from the line of the set. This is especially true if you use third-party applications for calls or are used to certain combinations. Although modern Xiaomi smartphones have a user-friendly graphical interface, knowing the codes can save you in situations where the touchscreen reacts with a delay.
One of the most useful methods is to use prefixes before a phone number. In a standard Google and MIUI call, you can add a prefix of 1 or 2 before the number in the contact so that the call always goes through a particular SIM card. However, a more universal way is to use access codes that depend on the operator, but in the context of selecting the SIM card on the device itself, the work differently.
In reality, at the Android level, codes are often referred to as fast menu commands, but when it comes to dialing codes, they are more commonly used to redirect calls, but there is an important caveat: if you dial a number from a call history, the system often suggests you pick up a SIM card if the last call to that caller was made from a different card, which is a kind of smart code of behavior of the system.
For those who like the technical approach, it is worth mentioning the possibility of using the USSD-You can use commands to check the balance and rates of the second SIM card to make sure you can call. For example, if you type *100# (conditionally) for the second card, you quickly know whether to call it. Although this does not switch the SIM card, it is an important stage in preparing for the call.
Secret codes for communication diagnostics
Automation of calls through contacts
One of the most convenient features in Xiaomi smartphones is the ability to pin a specific SIM card to a specific contact, which eliminates the need to remember each time you call your mom and a colleague, the system remembers your choice and automatically offers the desired card on the next call to this subscriber.
To set this up, you don't have to go to complicated menus. Just call the contact by manually selecting the SIM card you want. Once the call is complete (or even during it), the system will record that choice. Next time you open the contact card or find it on the list, the call button will display an icon next to the exact SIM card you used earlier. This works for both incoming and outgoing if you use the callback feature.
If you want to change your anchor, just call the same contact, but choose a different SIM card. The MIUI algorithm will update the rule for that number. This is especially useful for separating areas of life: all contacts from the Work group will automatically call from the corporate SIM card, and Family from the personal one, even if the global settings are priority work.
☑️ Setting up smart calls
It is worth noting that this feature works most consistently with the standard phone book Xiaomi and Google Contacts. When using third-party syncs, conflicts can occur when the system “forgets” preferences. In this case, it is recommended to clear the cache of the Phone application through the Settings menu → Apps → All applications → Phone → Memory → Clean.
Table of comparison of methods of SIM card selection
To organize information and choose the most suitable way to manage calls, let’s compare the basic methods for their effectiveness and convenience.
| Method of selection | Speed of access | Flexibility | Risk of error |
|---|---|---|---|
| Global priority | High (automatically) | Low (one number for all) | High (you can forget to switch) |
| Manual selection in the call | Medium (to be tapped) | High (for every call) | Medium (depending on care) |
| Contact binding | High (automatically) | Medium (for acquaintances only) | Low (the system remembers the choice) |
| Always ask | Low (excessive action) | Maximum | Minimum (you consciously choose) |
As you can see from the table, there is no perfect solution for all situations, and the best strategy is to use a combination of methods: to set Always Ask as the baseline, but for the most frequent contacts, use binding to speed up the process, which will keep cost control and not waste too much time switching.
Solving the problem: when the second SIM card does not ring
Despite the debugging of the Android system on Xiaomi devices, users can face situations when a call from the second SIM card simply does not pass, breaks down or the phone offers to use the first. The most common problem lies in network settings or signal overlap, especially if both SIM cards are in mode. 4G/LTE.
One of the common causes is a conflict of modes of operation.