VoLTE on Xiaomi Redmi 9: A Complete Guide to Setup and Fix Problems

Xiaomi Redmi 9 is one of the most popular budget smartphones, but many owners still do not use its capabilities to the full. One of these “hidden chips” is VoLTE technology (Voice over LTE), which radically changes the quality of voice communication. If you still call the old-fashioned way through 2G/3G, and while talking the Internet disappears, this article is for you.

We will discuss in detail what VoLTE is on Redmi 9, how to turn it on (including if the option is hidden in the settings), which carriers support the technology in 2026, and what to do if VoLTE does not work despite all efforts, and also uncover myths about increased battery consumption and the “harm” of the technology to health.

Spoiler: once you set up VoLTE, you'll forget about subway interruptions, a robot in the tube, and a long connection to the subscriber. SIM-Cards are compatible with the technology, even if the smartphone supports it out of the box».

What is VoLTE and why is it important for Redmi 9?

VoLTE (Voice over LTE) — This is a voice transmission technology over the network. 4G, Unlike traditional calls that are made 2G or 3G. The main advantage is that the quality of the connection becomes comparable to the IP-Telephony (like WhatsApp or Zoom) but works via a regular phone number.

On the Xiaomi Redmi 9 (M2003J15SC, M2004J19G, etc.), VoLTE is supported at the hardware level, but often disabled by default. Why is this critical for a budget smartphone?

• 📶 Quick connection: no delay of 2-5 seconds when dialing (as in the case of a phone call) 2G).
• 🎤 Clean sound: noise cancellation and wide range of frequencies (HD-voice – you will hear the whisper of the interlocutor.
• 🌐 Internet during a call: you can simultaneously talk and use instant messengers, maps or social networks.
• 🔋 Battery savings: You don’t have to switch between the two 4G and 2G, reduces the load on the modem.

Without VoLTE, your Redmi 9 falls from 4G to 2G/3G when you call, and then rises again after you talk — not only slowly, but also consumes additional energy, especially in places with unstable coverage (for example, in underground passageways or on the outskirts of cities).

How to check if your Redmi 9 VoLTE is supported

Not all versions of the Redmi 9 are the same, for example, the global model M2004J19G officially supports VoLTE, and some regional modifications (for example, for India) may have limitations.

1. Check the phone model: go to Settings → About Phone → Model. If there is a Global or EEA in the title, chances are VoLTE is supported.
2. Make sure you have the latest firmware installed: Settings → About Phone → System Update. VoLTE requires MIUI 12 or later.
3. Check carrier compatibility: not all Russian and foreign providers support VoLTE on Xiaomi.

If your carrier is not on the list or you use a virtual provider (like Tinkoff Mobile or SberMobile), VoLTE is likely to fail – these companies often rent networks from the “big three” without support for advanced features.

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To know if you are supporting your SIM-VoLTE card, call the operator and ask: "Do I have a voice service connected via the phone?" 4G (VoLTE)??. Sometimes it needs to be activated manually through your personal account.

Step-by-step: how to turn on VoLTE on Redmi 9

If your phone and carrier support the technology, you just have to activate it in the settings, and depending on the version of MIUI, the path may be slightly different, but the general scheme is this:

Make sure that SIM-The card is inserted into slot 1 (main card)

Update your firmware to the latest version of MIUI

Restart your phone before setting up

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

1. Open the Settings. → SIM-maps and mobile networks.
2. Choose yours. SIM-card (if two of them).
3. Tap on Network Type and select 4G (preferably) or LTE.
4. Go back and find VoLTE Calls (or Improved Calls) and switch to the right.
5. Confirm the action if a warning appears.

If the VoLTE call item is not on the menu, it means:

• 📱 Your firmware is outdated (update it).
• 📡 The operator does not support VoLTE for your tariff.
• 🔧 The option is hidden (see the next section).

Once turned on, an HD or VoLTE icon will appear next to the network indicator. To check whether you are working, call another phone — if the connection is instantly established and the sound is cleaner, everything is set up correctly.

Hidden VoLTE settings: how to turn on if the options are not in the menu

Sometimes a manufacturer or operator will block access to VoLTE settings at the software level, and in the case of Redmi 9, this is most often due to:

• 🌍 Regional restrictions (e.g., the phone is purchased for the Indian or Chinese market).
• 📦 Firmware from the operator (for example, MTS or Beeline can hide the options).
• 🔄 An outdated version MIUI (up to 12.0.3).

There are two ways to get around the lock:

Method 1: through the Engineering Menu (for advanced users)

⚠️ Attention: Incorrect actions in the engineering menu may disrupt the network!

1. Open the Phone app and dial ##4636##.
2. Select Phone Information (or Phone Information).
3. Scroll down to Set preferred network type and select LTE only.
4. Go back and find the VoLTE provisioned option – if you have one, turn it on.

Method 2: through editing settings (requires root)

If the engineering menu does not help, you can manually change the configuration files:

1. Install a file manager with root access (e.g., Root Explorer).


2. Go on the path: /data/data/com.android.providers.telephony/databases/telephony.db.




3 Open the file in the text editor and find the string with carrier_volte_available.




4. Change the value from 0 to 1.




5. Save, reboot the phone.

⚠️ Note: Editing system files without root rights or experience can cause your phone to crash. If you're not sure, you should contact the service center.

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On Redmi 9 with Xiaomi.eu firmware, VoLTE usually works out of the box, even if it doesn’t exist in standard MIUI, and it’s one of the most reliable ways to activate the technology.

VoLTE vs Wi-Fi Calling: Which is the best for Redmi 9?

Many people confuse VoLTE and Wi-Fi Calling, but they are different technologies with different advantages. Redmi 9 can use both — the main thing is to understand when it is more useful.

The ideal scenario is to use VoLTE on the street and in places with good quality. 4G-Wi-Fi Calling is available at home or in the office, where the mobile network is weak. On Redmi 9, both functions can be enabled simultaneously:

1. Settings → SIM-maps and mobile networks → Wi-Fi call.
2. Activate the option and follow the operator’s instructions (SMS confirmation may be required).

⚠️ Note: With active Wi-Fi Calling, the default calls will go over the Internet, even if VoLTE is available.To prioritize VoLTE, turn off Wi-Fi or change the settings in the menu SIM-map.

Common VoLTE issues on Redmi 9 and their solutions

Even if you set it up correctly, VoLTE can malfunction, and here are the typical symptoms and ways to treat them:

Problem 1: VoLTE is turned on, but calls are going through 2G/3G

• 🔄 Solution: Reboot your phone and force your network to select 4G manually (Settings) → SIM-map → Type of network → Only LTE).
• 📱 Solution: Check if the phone is not a restriction on background data transfer for the Phone application.

Problem 2: VoLTE sign appears, but the sound is interrupted

• 🎧 Solution: Disable Bluetooth headset – sometimes it conflicts with VoLTE codecs.
• 📡 Solution: Check the strength of the signal 4G. If less than 2-3 sticks, VoLTE can be automatically shut down.

Problem 3: VoLTE works, but the battery goes down quickly

It's a myth that VoLTE saves charge because it doesn't require switching between networks. If the battery runs out faster, it's not VoLTE's fault, it's:

• 🔋 Background applications (check in Settings) → Battery).
• 📶 Weak signal. 4G (Your phone is wasting energy on finding it).
• 📲 Outdated firmware (update) MIUI).

Problem 4: Operator says VoLTE is connected, but there is no badge on the phone

Possible causes:

• 📋 SIM-The card is not tied to VoLTE (call the operator and ask to “title” IMS-profile»).
• 🔧 Phone's off. IMS-Services (include in the engineering menu, see above).

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If after turning on VoLTE mobile Internet disappeared, check APN-settings. Sometimes they reset. Pathway: Settings. → SIM-map → Access points (APN) → Reset to factory

VoLTE and Health: Is Technology Really Bad?

There's a myth on the Internet that VoLTE is more dangerous than regular calls because of "radiation."

• 📡 4G (LTE) radiates less than 2G/3G. During a VoLTE call, the phone uses the same network as it does for the internet – there is no “additional” radiation.
• ⚡ The MoSCoW (International Safety Standard) confirms that the SAR (Radiation absorption in VoLTE is lower than in traditional calls due to more efficient data transmission.
• 🧠 No evidence of harm: World Health Organization (WHO) classifies mobile phones as "possibly carcinogenic" (group) 2B), This is true for all communication technologies, not just VoLTE.

If you are concerned about radiation:

• Use a headset or Bluetooth headphones.
• Do not hold your phone close to your head while you are calling (even with VoLTE).
• Prefer Wi-Fi Calling at home – the radiation of the Wi-Fi router is weaker than that of the 4G tower.

Bottom line: VoLTE is no more dangerous (and, according to some reports, even safer) than regular calls. The main "vrid" is a myth that arose from a lack of understanding of the technology.

FAQ: Answers to Frequent VoLTE Questions on Redmi 9