Wi-Fi Calls on Xiaomi Redmi Note 9: How to turn on and configure VoWiFi in 5 minutes

The Wi-Fi (VoWiFi) feature on the Xiaomi Redmi Note 9 allows you to make and receive calls even when you don’t have a cellular operator network — a fairly stable Internet connection. This is especially useful in areas with poor 4G/3G coverage, such as basements, remote villages or country houses. However, many users are faced with the fact that the option is either not on the menu or does not work after activation. In this article, we will discuss all the ways to enable VoWiFi on the Redmi Note 9 (including the Note 9 Pro, Note 9S and Note 9T models), and explain why the feature may not be displayed and how to fix it.

VoWiFi (Voice over Wi-Fi) technology uses a protocol IMS (IP Multimedia Subsystem, which is integrated into modern carrier networks. It is important to understand that the support of the function depends not only on the smartphone, but also on your mobile operator - not all providers in Russia and the CIS provide this service. 4G), It's probably VoWiFi is available, too. Next up is a step-by-step, nuanced instruction.

⚠️ Note: Redmi Note 9 with older firmware MIUI 12.5 The path to VoWiFi settings may be different. If you have custom firmware installed (like Pixel Experience or LineageOS), the feature may work differently or not at all.

1. Verify your operator’s VoWiFi support

Before you set up your smartphone, make sure that your mobile operator supports the technology. In Russia and the CIS, VoWiFi officially provides:

• 📡 MTS – available for subscribers with tariffs “Ultra”, “Smart” and corporate lines (activation is required via *111#).
• 📡 Beeline - works on the tariffs "Everything is simple", "No Limit" and "Digital" (check by check on the "It's simple" USSD-code *102#).
• 📡 MegaFon – supported on most tariffs, but requires the inclusion of VoLTE (dial *505#).
• 📡 Tele2 – limited support, only for new rates “My Online” and “My Conversation".
• 📡 Yota – VoWiFi is available by default for all subscribers.

If your operator is not on the list, check the current information on its official website or contact support. For example, in Ukraine VoWiFi is actively developing Kyivstar and Vodafon, and in Kazakhstan - Kcell and Tele2 KZ.

⚠️ Note: Even if the carrier supports VoWiFi, the feature may be blocked for a specific region or SIM-For example, MegaFon sometimes restricts VoWiFi for corporate customers with special rates.

2. Requirements for smartphone and firmware

To run VoWiFi on Redmi Note 9:

• 📱 Smartphone model: Redmi Note 9 (codename merlin), Note 9 Pro (joyeuse), Note 9S (curtana or Note 9T (cannon).
• 🔄 Version. MIUI: 12.0.1.0 or later (check in Settings) → The phone. → Version. MIUI).
• 📶 Active VoLTE: Calls on 4G Should work (if VoLTE is disabled, VoWiFi will not work either).
• 🔋 Security Updates: All latest patches installed (check in Settings) → Updating the system).

If you have custom firmware (e.g. Xiaomi.EU or ArrowOS), VoWiFi may not work properly or will not work, in which case we recommend returning the official MIUI Global or MIUI Russia.

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If in Settings → SIM-maps and mobile networks no item "Calls over Wi-Fi", update the firmware through Settings → Update the system or manually download the latest version MIUI Xiaomi.

3. Step-by-step instructions for turning on VoWiFi

If all conditions are met, follow this instruction:

1. Open the settings on your Redmi Note 9.
2. Go to section. SIM-maps and mobile networks.
3. Choose yours. SIM-card (if two of them).
4. Slip on the item Calls over Wi-Fi (or Wi-Fi Calling on English firmware).
5. Activate the Wi-Fi Call Switch.
6. In the window that appears, select Connect automatically or only if there is no network.

When you turn on next to the network indicator, the status bar will show you a VoWiFi or a wave tube icon. If there is no icon, restart the phone.

Critical nuance: Some Redmi Note 9 firmwares have the Wi-Fi Calls hidden unless VoLTE is activated. First turn on VoLTE in the same menu, then go back and check for VoWiFi.

4.Why VoWiFi doesn't work: Common problems

If Wi-Fi calls are not functioning after activation, the reasons may be as follows:

• 🚫 Operator does not support: Check with support if the service is available for your rate.
• 🔌 Unstable Wi-Fi: VoWiFi requires speeds of at least 2 Mbps and pings below 100 ms.
• 📵 No VoLTE: No active calls to 4G VoWiFi won't work.
• 🔄 Failure IMS-Services: Restart your phone or reset your network settings (Settings) → System system → Reset → Resetting network settings).
• 🛠️ Castom firmware: VoWiFi may not be available on unofficial builds.

⚠️ Note: Redmi Note 9 with firmware MIUI 11 and below VoWiFi may not work properly due to outdated IMS-Update to protocols. MIUI 12.5+.

5. Alternative ways to enable VoWiFi

If the standard method doesn’t work, try these options:

Method 1: Engineering menu (for advanced users)

Enter the phone code in the appendix:

##4636##

Go to Phone Information → Choose yours. SIM-map → Scroll down to VoWiFi provisioned. If status 1, function is active. If 0, contact operator.

Method 2: Reset network settings

Sometimes resetting helps to wake up" IMS-service:

1. Go to Settings → System → Reset.
2. Select Network Resetting.
3. Confirm the action and restart the phone.

Method 3: Manually Update Operator Configuration

Remove and add again SIM-map:

1. Open the Settings. → SIM-maps and mobile networks.
2. Tap it on. SIM-map → Delete.
3. Reboot your phone and add the SIM again.

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If VoWiFi doesn’t appear in the settings even after all the manipulations, chances are your carrier doesn’t support the feature or you need to update your firmware to MIUI 12.5+.

6. Comparison of VoWiFi and VoLTE: Which is better?

Many users confuse VoWiFi and VoLTE, although these are different technologies:

On the Redmi Note 9, both technologies can work simultaneously: if you are in 4G coverage, VoLTE will be used, and if it is not available, you will automatically switch to VoWiFi.

Example: You go down to a basement where there's no cellular network, but there's Wi-Fi, and the call goes through VoWiFi, and when you go outside, the smartphone goes back to VoLTE.

7. How to turn off VoWiFi (if necessary)

If you notice connection problems or increased battery consumption, VoWiFi can be deactivated:

1. Go to Settings. → SIM-maps and mobile networks.
2. Choose yours. SIM-map.
3. Slip on Wi-Fi calls.
4. Turn off the switch.

You can also temporarily pause the function through the notification bar: swipe down from the top edge of the screen and hold the VoWiFi icon (if any).

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If all mobile data is lost after the VoWiFi shutdown, restart the phone or turn on the “On the plane” mode for 10 seconds, then turn off.

FAQ: Frequent questions about VoWiFi on Xiaomi Redmi Note 9