Wi-Fi Call on Xiaomi: How it Works and Why

Have you ever seen a situation where a mobile network suddenly disappears and the call still passes? Or noticed that in the subway or basement, a Xiaomi smartphone suddenly shows the inscription “Call over Wi-Fi” instead of the usual operator? It’s not magic — it’s Wi-Fi Calling technology, which has been integrated into MIUI firmware for several years. But how it works in practice, which Xiaomi models support it, and why sometimes Wi-Fi calls do not connect — let’s figure it out in order.

In 2026, most of Xiaomi’s current smartphones (from the budget Redmi Note to the flagship Xiaomi 14) support this feature, but activation depends not only on hardware capabilities, but also on the carrier. In this article, you will find a step-by-step setup instruction, a comparison table of compatibility with Russian carriers, and unique data on hidden MIUI settings that help stabilize the connection. If you have not used Wi-Fi Calling before, after reading, you will understand why you were wasting your time.

What is Wi-Fi Calling on Xiaomi and How it Works

Wi-Fi Calling (or VoWiFi) technology allows voice calls and SMS to be sent over a Wi-Fi connection instead of a traditional cellular network. This is not the same as instant messengers like WhatsApp or Telegram – it uses a standard phone number, and calls are charged as normal (or free if you have unlimited calls).

How it works for Xiaomi:

• 📶 The smartphone connects to a Wi-Fi network (home, office or public).
• 🔄 If the mobile network signal is weak or absent, the system automatically switches to voice transmission over the Internet (provided that the function is enabled).
• 📞 The bell goes through IMS-Operator server, not through cell towers.
• 🔒 Traffic encryption ensures conversation security (unlike some VoIP applications).

The main advantage is the stability of communication in areas with poor coverage, for example, in basements, elevators, remote areas or outside the city where LTE/4G does not catch, but there is Wi-Fi, and the subscriber at the other end of the wire will not even notice the difference — for him it is a regular call.

But there are nuances:

• ⚠️ Not all operators support VoWiFi (in Russia for 2026 it is MTS, Beeline, MegaFon and Tele2, but with restrictions).
• ⚠️ On some Xiaomi models, the feature is hidden in the engineering menu and requires manual activation.
• ⚠️ In roaming Wi-Fi Calling can work differently – depends on the agreements between operators.

What Xiaomi models support Wi-Fi Calling

VoWiFi depends on two factors: hardware support for the smartphone and the version of the MIUI firmware. Below is the current list of models for 2026 that are officially compatible with the technology (including firmware updates):

Important: Even if your model is on the list, the carrier must support VoWiFi, for example, Yota and Tinkoff Mobile are not providing this service at the time of writing.

How to check support on your smartphone:

1. Open the settings → About the phone → version of MIUI.
2. If the firmware version is older than 2022, update it through Settings → System Update.
3. Check for the “Call over Wi-Fi” item in Settings → SIM-maps and mobile networks → [yours SIM] → Calling over Wi-Fi.

How to enable Wi-Fi Calling on Xiaomi: step-by-step instructions

Activation of the function takes no more than a minute, but the algorithm may vary depending on the version of MIUI. Below is a universal instruction for most models:

Connect to a stable Wi-Fi network

Make sure that SIM-The card supports VoLTE (4G-call-up)

Update the firmware to the latest version

Check the balance (some operators block the function when the balance is negative)-->

Step 1. Open Settings and go to the section SIM-maps and mobile networks.

Step 2. Choose yours. SIM-card (if there are several).

Step 3: Find the “Call over Wi-Fi” (or “Wi-Fi Calling”) item and activate the slider.

Step 4: Confirm the activation if a request from the operator appears (sometimes a reboot is required).

Step 5: Once activated, a Wi-Fi icon with a tube will appear in the status bar (📞).

If the item is not on the menu, try an alternative way:

1. Enable Developer Mode: 7 times click on "Version MIUI" in "About Phone".


2. Go back to "Settings → Additional → For Developers."




3. Find "Wi-Fi Calling" and turn it on manually.

💡

If the calls don’t go through after turning on, try to turn off the call. VPN alter DNS-server in Wi-Fi settings at 8.8.8.8 (Google) or 1.1.1.1 (Cloudflare).

Why Wi-Fi Calls Don’t Work on Xiaomi: 7 Reasons and Solutions

Even if the feature is activated, Wi-Fi calls may not connect, and here are the most common reasons and ways to eliminate them:

1. Operator does not support VoWiFi. Solution: Check the list of supported operators on their official sites. For example, MTS requires a connected service called Voice over Wi-Fi (free).
2. Outdated firmware. Solution: Update MIUI to the latest version via Settings → System Update.
3. Failure IMS-Registration.Solution: Go to Settings → SIM-map → [yours SIM] → Additionally. → Registration IMS and press "Update».
4. Firewall or VPN blocking Solution: Disable the VPN and temporarily deactivate the antivirus (e.g., Avast or Kaspersky).
5. Wrong settings APN. Solution: Reset the settings APN to standard: Settings → SIM-map → Access points (APN) → Reset.
6. Problems with Wi-Fi router. Solution: Reboot the router and check if it supports IPv6 (required for VoWiFi).
7. Roaming restrictions: Solution: If you are abroad, check with the operator if international Wi-Fi Calling is enabled.

If nothing helps, try resetting your network settings:

Settings → System → Reset → Network settings reset

💡

On some Xiaomi firmware (especially Chinese), Wi-Fi Calling only works with Chinese carriers, in which case flashing to the global version of MIUI will help.

Wi-Fi Calling vs VoLTE: What’s the difference and what’s better

Many people confuse Wi-Fi Calling and VoLTE, but these are two different technologies with different working principles.

So what's better? The ideal is that both technologies are on at the same time, in which case the smartphone will automatically switch between VoLTE and VoWiFi depending on the availability of the network.

• 🏠 Home (where good Wi-Fi) – VoWiFi will be used.
• 🚗 Outside (where stable) 4G) — switch to VoLTE.
• 🏢 In an office with a poor mobile signal, VoWiFi is back.

On most Xiaomi smartphones, both features are included in the same menu: → SIM-map → [yours SIM] → Calling over Wi-Fi / VoLTE.

Hidden MIUI settings to improve Wi-Fi Calling

If the standard settings do not give a stable connection, MIUI has a few hidden settings that can be changed through the engineering menu or ADB.

1. Forced VoWiFi activation through code:

##4636## → Phone information → Wi-Fi Calling → Enable

This method works on Xiaomi 12/13/14 and some Redmi Notes.

2. Change of priority of the network:

→ SIM- Card settings → [your SIM] → Network type → Prefer Wi-Fi Calling

This option forces the smartphone to use VoWiFi even when there is a weak mobile signal.

3.Dumping IMS-configuration:

Settings → Applications → Application Management → Three dots (⋮) → Show system → IMS Service → Storage → Clear data

It helps if the calls stop in 10-20 seconds.

4. set up MTU for VoWiFi (for advanced users only):

adb shell settings put global wifi_calling_mtu_size 1400

Reducing packet size can improve stability on slow Wi-Fi networks.

💡

If after changes in the engineering menu, the mobile signal disappeared, perform a network reset (Settings → System → Reset → Network settings reset) or restart the smartphone.

Wi-Fi Calling Security: Myths and Reality

Many users fear that Wi-Fi calls are less secure than normal ones.

Myth 1: “Whi-Fi calls are easier to listen to.”

Reality: VoWiFi is using the IMS-encryption SRTP, It's a phone call that's as hard as a bank transaction, and it's harder to listen to a call like that than a regular call. GSM (where the signal is transmitted in plain form).

Myth 2: “Wi-Fi Calling is a lot of traffic.”

Reality: The average call consumes ~1MB/minute (with the Opus codec). By comparison, watching a YouTube video as 480p eats ~10MB/minute.

Myth 3: “The function only works on secure Wi-Fi networks.”

The reality is that VoWiFi will work even on open networks (like a cafe) but in this case, the risk is not enough. MITM-It is recommended to use Wi-Fi with a password or VPN.

⚠️ Note: If you are connected to public Wi-Fi (e.g. at an airport), attackers can theoretically intercept the metadata of the call (number, duration), but not the content of the conversation itself. VPN supportive IKEv2 WireGuard.

To check if your call is secure:

1. During the conversation, open the settings → Wi-Fi.
2. Click on your network and check the security type (should be WPA2/WPA3).
3. If the network is open, clean the cache in Settings → Apps → Phone → Storage → Clear the cache after the call.

FAQ: Frequent questions about Wi-Fi Calling on Xiaomi