VoWiFi on Xiaomi: how to enable and configure calls over Wi-Fi

The modern rhythm of life requires constant availability, but the quality of cellular communication is not always in line with the expectations of users. In new residential complexes, offices with thick walls or in country houses, the signal of base stations is often lost, turning a smartphone into a useless piece of plastic, it is in these situations that VoWiFi (Voice over Wi-Fi) technology, which allows voice calls over the Internet, comes to the rescue.

For Xiaomi, Redmi and POCO devices, activating this feature can be a real lifeline, but the process of turning on is not always obvious. Unlike some other brands, the Chinese manufacturer often hides the necessary switches in the back of the engineering menu or hides them depending on the region of the firmware. Understanding how to circumvent these restrictions is critical for stable communication.

In this detailed guide, we will look at all aspects of setting up voice calls over Wi-Fi, and we will look at standard activation methods, using special codes to open hidden settings, and solving typical problems that subscribers of various operators face in 2026.

What is VoWiFi and why does the owner of Xiaomi need it?

Voice over Wi-Fi is not about sending voice traffic through traditional GSM/3G/4G radio channels, but rather via IP protocols using any wireless connection available. For the user, this means that the operator's network coverage extends to the limits of the Wi-Fi router's availability. If your Xiaomi smartphone sees a wireless network, it will be able to receive and make calls even in a basement or a building with shielded walls.

The main advantage is not only the stability of the connection, but also the savings in battery power. In the conditions of a weak signal of the cell tower, the communication module begins to work at its limit, actively consuming energy to maintain the link. Switching to VoWiFi reduces the load on the radio module, since the distance to the access point is minimal. HD-Wi-Fi format often exceeds standard cellular network quality.

⚠️ Attention: The quality of the call depends on the speed and stability of your Internet connection. When the channel is congested or high ping, audio delays or connection breaks may occur.

It is important to note that this feature only works with support from the operator. In 2026, most major providers have already implemented this service, but it may require additional activation in the personal account or plan.

Verification of device and operator compatibility

Before you start to manipulate the menu, make sure your hardware and SIM card are technically ready to go. Not all Xiaomi models, especially those released a few years ago, have hardware support for the necessary protocols. Also, the version of the HyperOS operating system plays an important role, or MIUI.

The first step should always be to check the status of the service with your mobile operator, even if the phone supports the technology, without the appropriate setting on the provider side, nothing will work. Often subscribers spend hours setting up the phone, forgetting that the service is simply not connected on their number.

For quick diagnosis, you can use the following checklist, which will help weed out obvious problems:

• 📱 Make sure that the latest available firmware version is installed on the smartphone via the update menu.
• 📡 Check if your plan supports voice calls over the internet (often required) 4G/LTE tariff).
• 🔒 Make sure that the SIM card is not old. PIN-Codes or restrictions that block additional services.
• 🌍 Note the region of the device: Global versions may differ from Chinese versions (CN) List of supported operators.

Keep in mind that the list of supported operators is stitched into the system firmware files. If your provider is not on this list, the standard switch may not appear in the settings, and then you will have to resort to more advanced activation methods, which will be discussed below.

Statutory activation through system settings

In most cases, if the operator officially supports the service and your SIM card is determined correctly, the function is activated automatically or through the standard menu. MIUI It assumes the presence of a dedicated switch in the settings section SIM-map.

To check, go along the way: Settings → SIM-maps and mobile networks → Choose yours. SIM-Here, in the additional settings, there should be a Wi-Fi call. If you see this switch, just activate it. In some cases, the system may suggest that you choose to prioritize: "Prefer Wi-Fi" or "Prefer mobile network".

💡

If the switch appears but does not activate (turns off immediately), try to turn on the flight mode for a few seconds, and then turn it off while in the Wi-Fi range.

Sometimes the interface may hide this option if the smartphone thinks the current Wi-Fi connection is unstable. Try to force the switch to Wi-Fi Only mode in the mobile network settings to check the system response. Also, rebooting the device after inserting the SIM card helps, since it is at the time of booting that the initial exchange of profiles with the operator occurs.

If it's on the menu SIM-The card is empty or the item is missing, which is a sure sign that the automatic operator detection has not worked, and in such a situation, you need to move to manual methods of activating hidden functions of the system.

Activation through engineering menu and codes

When standard methods don’t work, hidden engineering menus come to the rescue that allow you to force VoWiFi support on, which is the most effective way for devices where the operator is not listed officially, but technically a service is provided. To access these settings, we will need the “Engineering Menu” application or enter a special one. USSD-code.

Try typing the code ##869434## in the standard Phone app. This code is designed to activate VoLTE, but on many modern Xiaomi models it will also unlock related features, including Wi-Fi Calling. Once you enter the code, you should see a pop-up notification that the mode is activated.

Enter in the call: ##869434##


Wait for vibration or notification "VoLTE carrier check enabled"




Reset the device

If the code doesn't work, you can use Activity Launcher or similar tools to find hidden system activities. Find an activity called CarrierConfig or ImsService on the list, and these menus often contain "Enable VoWiFi" or "Carrier VoWiFi not available" ticks, which are forced to include a feature.

⚠️ Warning: Be extremely careful in the engineering menu. Changing unknown parameters can lead to malfunctioning of the radio module or loss of the network. IMS VoWiFi.

Once you make the changes, make sure you reboot your smartphone completely. Only after you turn the system on and re-search the network, the new settings will take effect. If the Wi-Fi phone icon doesn't show up, try making a test call.

Setting up APN and IMS profiles

A key element of voice services over the Internet is the correct access point profile (APN), which prescribes the IMS (IP Multimedia Subsystem) parameters that are responsible for multimedia services, including voice. If your operator's profile does not have the necessary fields, VoWiFi will not work.

To edit, go to Settings → SIM-maps and mobile networks → Choose. SIM → Access points (APN). Click on the active profile (usually marked with a green dot) and carefully examine the fields. APN type APN protocol.

In the field APN If it says only "default,supl," add the word "ims" through the comma, the line should look something like this: default,supl,ims. IPv4/IPv6, Some operators require a dual-stack protocol to transmit voice traffic.

Below is a table with examples of APN settings for popular carriers, where automatic configuration is often difficult:

After making changes, be sure to click the Save button (usually three dots in the corner of the screen or a separate button at the bottom) and select this profile as active. Without saving, the configuration will not apply, and the phone will continue to use old, non-working options.

Solving problems and eliminating mistakes

Even after setting up properly, users may find themselves in situations where the VoWiFi icon is not on and calls are disrupted. One common reason is the conflict between network modes. If a phone tries to cling to a weak 3G/4G signal instead of a stable Wi-Fi, priority may be given to the mobile network.

Try temporarily switching network mode to 4G Only (LTE), which will force the phone to ignore old communication standards that do not support voice over IMS, and force it to use available Wi-Fi for calls, and also helps to disable the Wi-Fi Assistant feature, which can automatically switch the phone to mobile Internet when perceived Wi-Fi signal deterioration.

Another common problem is the incompatibility of the firmware region: Chinese versions of Xiaomi with a global SIM card (or vice versa), there can be frequency and setting conflicts, in which case changing the region in the phone settings (without flashing) to your carrier’s country helps, which forces the system to tighten the correct configuration files.

⚠️ Note: If you use a dual-sim phone, VoWiFi can only work on one. SIM-If you call the second SIM, the Wi-Fi connection on the first one may be interrupted.

In case of persistent problems, it is recommended to reset the network settings.This action will return all mobile, Bluetooth and Wi-Fi parameters to factory values by removing possible configuration software errors. → Connection and sharing → Reset Wi-Fi, mobile networks and Bluetooth.

Frequently Asked Questions (FAQ)