Owners of modern Xiaomi smartphones often face the need to use two SIM cards at the same time, which may be due to the separation of personal and work contacts or the desire to save on tariffs of different operators. However, standard setting of the device often involves automatic selection of one of the cards for all outgoing calls, which creates confusion in moments of urgent calls.
The MIUI shell interface or the new HyperOS has many hidden features that allow you to flexibly manage communication priorities. Understanding the logic of communication modules will help you avoid missed calls and unnecessary costs. In this article, we will discuss in detail all the ways of forced dialing, as well as the automation of this process.
Incorrect configuration can lead to the fact that an important call will go on the balance of the main SIM instead of the corporate one, or vice versa. To avoid this, you need to correctly configure the call parameters in the system menu. We will consider both standard tools and the nuances of working with specific models of devices.
Basic setting of call priorities
The first thing to do after installing new SIM cards is to set the right priorities in the system. Xiaomi allows you to assign one of the SIM cards as the default voice communication, which means that when dialing from a phone book or call history, the system will automatically use the selected line.
To change these settings, go to the Settings menu and find the section SIM-Maps and mobile networks. This shows both cards installed with their current status. Clicking on Default for Calls, you'll see the list of available carriers and the option "Always ask." Choosing the last option will cause the phone to request a SIM card before each set.
⚠️ Warning: If you have selected the “Always Ask” option, but the phone still rings from one particular SIM, check if the “Remember Choice” box is set in the dial pop-up window.
It is important to note that settings may vary depending on the firmware version. In older versions of MIUI, the menu may have been deeper in the setting structure. Modern versions of HyperOS take these settings to the forefront for user convenience. Regularly check the relevance of settings after major system updates.
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The correct default priority setting eliminates the need to switch SIMs before each call.
Forced selection of SIM when dialing a number
Even if you have a priority for one SIM card, Xiaomi’s system makes it easy to switch to the second one right at the time of dialing. This is especially convenient when you need to urgently call from another number without changing the global settings of the phone.
If you have a question in the settings before each call, you will see a pop-up window with the choice of a SIM card when you press the call button in contact or history. However, if you choose automatically, the call button will have the color of the SIM that is active by default.
To call from the second SIM without changing the settings:
- 📞 Open a contact or number in your call history.
- 👆 Click not on the main big call button, but on the small icon of the second SIM card next to it.
- 🔢 When manually dialing numbers, click on the SIM card icon at the top of the screen before pressing the call button.
This allows you to keep the flexibility of communication. You can call for years from the main SIM, but at the right time quickly use a backup number. The interface of the buttons is intuitive: they are usually signed "SIM 1" and "SIM 2" or have carrier names.
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When dialing manually, you can click on the SIM card icon at the top of the screen to change the active line right while entering the numbers.
Configure calls for specific contacts
One of the most useful but little-known features in Xiaomi smartphones is the ability to pin a specific SIM card to a specific contact, ideal for those who conduct business correspondence and negotiations exclusively from a work SIM, and communicate with friends on a personal basis.
To implement this feature, open the Contacts or Phone app and find the person you want. In the contact card, usually at the top of the screen or in the optional action menu (three dots), there is a "SIM settings" or "Always use SIM" option.
The advantages of this setting are obvious:
- 🔒 Privacy: You will never accidentally call a customer from a personal number.
- ⏱ Time savings: you do not need to choose a SIM card every time you call a regular subscriber.
- 📊 Cost accounting: it is easier to control costs under different tariff plans.
It's worth noting that this anchoring only works for outgoing calls through the contact app. If you're dialing a number manually that's not stored in memory, the system will be guided by general prioritization settings, so it's best to still create phonebook entries for frequently dialed numbers.
What to do if the setting is not saved?
Work with 4G and VoLTE on two SIM cards
The question of the Internet and voice communication on two SIM cards at the same time is often difficult. DSDS (Dual SIM This means that both SIMs are active and receiving calls, but the data channel is still active (4G/LTE) At a particular time, you can only be active on one of them.
When you make or receive a call on a SIM card that is not the main one for data transfer, the connection can temporarily switch to 2G or 3G standards if VoLTE (Voice over LTE) is not enabled. For two SIMs to work in 4G mode, both operators need to support this technology and it is activated in the settings.
Verification and activation of VoLTE:
- 📶 Go to Settings. → SIM-maps and mobile networks.
- 📡 Select the desired SIM card from the list.
- ✅ Activate the “Use VoLTE” switch if available.
If your carrier does not support VoLTE, then during a conversation on one SIM, the second one may become unavailable or go into “out of range” mode. This is a technical limitation of the radio module, not a software bug. Using Wi-Fi Calling can also help to unload the radio channel, allowing you to stay in touch over the Internet.
Solution: SIM card is not selected or ringing
Users sometimes face a situation where the phone ignores settings or does not allow you to choose a second SIM card. Often the problem lies in a software failure of the telephony service or incorrect identification of the type of card. Before carrying the device to the service, you need to perform a number of diagnostic actions.
First of all, make sure that both SIM cards are correctly identified by the system. Two network icons should be on the status bar. If one is not present, check the density of the card in the tray. Sometimes contact oxidation or an old cropped chip can cause problems with registration on the network.
Table of possible problems and solutions:
| Problem. | Possible cause | Decision |
|---|---|---|
| No SIM choice when calling. | Phone app failure | Clear the app cache in the settings |
| Second SIM "offline" | Frequency conflict or VoLTE | Turn off 4G on the second SIM or enable VoLTE |
| Automatic resetting of settings | Mistake of MIUI Update | Reset network settings to factory |
| I can't hear the conversation on SIM 2. | Problems with the speaker or software | Check the work of speakers in the engineering menu |
If simple methods don't work, try resetting your mobile network settings. This action won't delete your personal data (photos, contacts), but will return all communication parameters to factory values. → Connection and sharing → Reset Wi-Fi, mobile networks and Bluetooth.
☑️ Diagnosing communication problems
Using third-party applications to manage calls
Xiaomi's regular tools are powerful, but sometimes the functionality may not be enough for specific scenarios, such as if you need to set up complex redirect rules or automatic responses depending on which SIM the call came to.
Dealer apps (alternative callers) often have a more flexible SIM management interface, which can display the balance of all operators on a single screen, keep detailed statistics on each SIM separately, and provide convenient widgets for quick switching, but be careful when giving such applications access rights.
⚠️ Warning: When installing third-party calling apps, carefully read the permissions requested.Do not give access to contacts and microphone to unverified developers to avoid data leakage.
Popular software can offer smart switching features by analyzing time of day or location, such as automatically activating a work SIM in the daytime and personal in the evening, and implementation of such scenarios at the system level in MIUI is limited, so third-party software becomes the only way out for advanced users.
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Third-party apps give more flexibility to manage, but can consume more battery power and require additional permissions.
Features of work in HyperOS mode
With the release of the new HyperOS operating system, which gradually replaces MIUI on Xiaomi devices, the visual design and logic of some menus have changed, fundamentally the algorithm for working with SIM cards has remained the same, but the layout of the elements has become more minimalistic.
In HyperOS, SIM card management is put into a separate widget in the notification curtain. Swipe down the screen, you can quickly switch the main SIM card for the Internet or temporarily disable one of them, which speeds up access to frequently used functions without diving deep into the settings.
It also improves profiles, makes it easier to create scenarios where the phone will suggest switching to a second SIM if the first one runs out of minutes or no signal, and makes the system smarter in analyzing the quality of communication and can recommend that the user change the priority card for an outgoing call if the current one shows a weak signal.