How to choose a default SIM card on Xiaomi Redmi

Modern smartphones Xiaomi Redmi line almost always equipped with two slots for the SIM-But when a device is just out of the box or after resetting, the question arises: How exactly should the system handle incoming calls and through which slot to access the network? MIUI HyperOS often requests action every time you call, which can be uncomfortable in everyday life.

Properly configuring communication priorities eliminates unnecessary confusion and saves battery power by preventing constant network search in an inactive slot. In this article, we will discuss in detail the algorithm of actions for installing the default card, look at the nuances of working with the mobile Internet and answer frequent questions that arise from owners of Redmi Note smartphones and other series. Understanding these settings is critical for the stable operation of the device.

Basic management settings in MIUI

The MIUI shell interface used in Xiaomi smartphones has a different menu logic than pure Android. To start the configuration, the user needs to go to the central hub for managing system parameters. Most often, the desired section is not hidden in deep submenu, but is accessible through quick access or basic communication settings. It is important to understand that the terminology may differ slightly depending on the firmware version (Chinese or global), but the essence remains the same.

The first step is always to go to the Settings menu, and here we're looking at the wireless connection unit. In newer versions of the interface, it's often called the Settings menu. SIM-And that's where all the levers of priority management are, and if you just inserted new cards, the system will suggest you set them up, but if you missed that step or you want to change your choices, you'll have to go manually.

Inside this section, you will see a list of installed cards with their names (e.g., "MTS", "Beeline" or simply "SIM 1"). Each card may have activation switches next to each. Slot activation is the first thing to check: if the slider is off, the card will not catch the network, and it will not be possible to select it by default. Make sure that both cards are displayed correctly and are "On" status.

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After installation SIM-The phone can't see the card, so try restarting the device without removing the trays, and 80 percent of the time, that solves the problem of initializing the chip.

Setting Priority for Voice Calls

The most common scenario for using two SIM cards is the separation of incoming and outgoing calls. Users often want one card to only take calls (for example, to check in with banks), and the other to actively communicate. SIM-There is a separate item in the cards, usually called Calls or Default Calls.

Clicking on this option will open a list of options available to you. You can choose a specific SIM card (SIM 1 or SIM 2) that will be the main one for dialing. The option is also available, "Always ask." Choosing this option means that each time you dial, the system will display a pop-up with a suggestion to choose a SIM, which is convenient if you often call different contacts from different numbers, but can be annoying when in a hurry.

It’s worth noting that the Xiaomi Redmi priority setting works globally for all applications that use a standard phone module, but some instant messengers or enterprise applications may have their own internal settings that ignore system preferences, in which case you need to change the settings inside the application itself.

Setting up mobile Internet and data transfer

Unlike voice calls, mobile internet on Xiaomi smartphones cannot work simultaneously with two SIM cards at full speed (except for rare aggregation modes that require operator support). So choosing a data card is a critical parameter. If this parameter is not configured, the Internet may not work at all or work through a zero balance card.

Same menu. SIM-You have to fix the SIM card, you have to fix it hard, you have to fix it, you have to fix it, you have to fix it, you have to fix it, you have to have unlimited rates or gigabytes. The system will not automatically switch to the card with the best signal for the Internet, unless you activate the corresponding “smart” functions, which will be discussed below.

At that point, the 4G/LTE icon may disappear for a few seconds, which is normal for the login protocol to be on the network, and if the Internet didn't show up after the change of setting, check if the "Mobile Internet" item is on in the notification curtain.

Smart Switching Function and Additional Parameters

The MIUI shell offers users advanced dual-SIM scenarios that go beyond simple default choices. One of these features is smart switching, which allows the system to automatically use the second SIM card for calls if the main one is not connected or busy, and this is especially true for business users who need to stay connected in any situation.

There is also a feature that allows you to take calls to the second SIM card while the first one is busy talking. SIM-There you'll find switches like Use the second. SIM for calls or Allow data switching.

Another important aspect is the default SMS setting, and although modern smartphones often tie texting to a specific contact or remember the last choice, the initial setup is also in this section, so you can assign a primary card to send an SMS so you don't have to manually select it every time you confirm codes or send messages.

⚠️ Warning: Automatic Internet switching when signaled poorly can cause unexpected traffic consumption from the main card if you are in the zone of uncertain reception of the second card.

Comparison of SIM card modes

To better understand which mode to choose, it is worth considering their impact on resource consumption and convenience. Different use cases require different approaches. Below is a table comparing the main modes of setting up SIM cards on Redmi devices.

As you can see from the table, fixed card selection is the most energy efficient and easy option. Always Ask is only useful in very specific cases where the user actively manipulates both numbers throughout the day. Smart switching is a trade-off between reliability and autonomy.

Solving Typical Problems and Errors

Often, users are faced with a situation where the settings are lost or stopped working after updating the system. For example, the phone may stop seeing one of the cards or the Internet begins to work unstable. In such cases, the first thing to do is to reset the network settings. This will not delete your personal data (photos, contacts), but return all communication parameters to factory values.

To do this, go to the Settings menu → Connection and Sharing (or Additional) → Reset Wi-Fi, mobile networks and Bluetooth. Once you do this, the phone will reboot, and you will need to re-select the default SIM card, often solving the modem's "glitch" problems.

Another common problem is that you can't choose 4G for a second SIM card, and many Xiaomi Redmi models have a technology that allows you to only use 4G on one card at a time, and then the second card is forced to go to 2G/3G mode to provide voice communication, which is a hardware limitation, not a software bug.

⚠️ Note: If the network has lost access points after resetting APN For the Internet, don't panic. They usually recover automatically when you restart. If that doesn't happen, contact the operator to get automatic settings through the service. SMS.

It is also worth mentioning the problem of blocking. SIM-If you've installed it, PIN-The code on the card, the phone will ask for it every time you reboot, and make sure you enter the code for the card that the system is requesting at the moment, because when you double-sim, the requests can go sequentially.

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Reset network settings is a universal solution for 90% of problems with the choice of SIM card and mobile Internet on Xiaomi.

Frequently Asked Questions (FAQ)