How to Make Wi-Fi Calls on Android: A Complete Guide

Many people are familiar with the situation where wireless coverage in an apartment or office is excellent, but mobile phone service drops out or is severely distorted. This occurs due to the nature of radio wave propagation: the base station signal has difficulty penetrating thick walls, rebar, and energy-saving double-glazed windows, while a home router provides stable internet. This is where technology comes in. VoWiFi, which allows you to make voice calls over the Internet, bypassing traditional cell phone towers.

Previously, to solve this problem, you had to install third-party apps like Skype or Viber, forcing your caller to do the same. Modern Android smartphones have a built-in feature that makes this process transparent: you dial a regular number, and the call is placed over Wi-Fi if the cellular signal is weak. In this article, we'll discuss how to activate this feature, the device and carrier requirements, and the setup nuances for different manufacturers.

Using this technology not only improves connection quality in remote areas but also often saves battery life, as the cellular module no longer constantly searches for the highest-power network. However, before setting it up, make sure your data plan and phone model support this feature. Menu interfaces may differ depending on the operating system version and the manufacturer's shell.

What is VoWiFi technology and how does it work?

VoWiFi stands for Voice over Wi-Fi, literally meaning "voice via Wi-Fi." Technically, it transmits voice traffic over IP network protocols, similar to how data is transmitted when browsing the web, but using special prioritization mechanisms to ensure minimal latency. Unlike instant messaging apps, which use their own servers and require both parties to install the app, VoWiFi is integrated into the standard smartphone dialer.

The key advantage is that for both the caller and the recipient, the process feels like a regular phone conversation. The number is automatically identified, caller ID is available, and call forwarding is even possible. IMS protocol (IP Multimedia Subsystem), used by operators, guarantees connection security and encryption, making conversations protected from eavesdropping on open networks.

It's important to understand the difference between VoWiFi and VoLTE. While VoLTE (Voice over LTE) transmits voice over 4G networks, VoWiFi uses any available internet connection. These technologies often work in tandem: when leaving Wi-Fi coverage, a call can seamlessly switch to LTE without disconnecting if the carrier and device support this handover feature.

⚠️ Please note: Connection quality directly depends on the stability of your internet connection. When using public Wi-Fi in cafes or airports, delays may occur due to high bandwidth usage or provider restrictions.

For the technology to function, support from three components is required: the smartphone itself, the carrier's software, and the data plan settings. If even one of these components is missing, the feature will not activate. Modern flagships and mid-range devices have long been equipped with the necessary module, but in budget models, it may be disabled by software.

Device and carrier requirements

The first step before setup is to check your hardware compatibility. Not all phones, even new ones, have Wi-Fi calling unlocked for all carriers. Smartphone manufacturers often negotiate with specific carriers to certify their devices, after which the appropriate profile is added to the firmware.

Owners of smartphones purchased from official retailers of major chains are usually more fortunate: these devices come pre-installed with profiles for all major carriers. However, if the phone is imported from abroad (for example, versions for the Chinese or US markets), the list of supported carriers may be limited. In this case, you may need to reflash the firmware or change the device's region (CSC), which is a complex procedure.

Telecom operators must also support VoWiFi in your region. Major national carriers have already implemented this technology in most major cities, but the infrastructure may not be ready in remote areas. Furthermore, the service must be active on your plan; some older plans don't have it by default.

There are several ways to check support. The easiest is to visit the operator's official website in the help or specifications section. Lists of compatible models are usually published there. You can also use USSD commands or your personal account, which sometimes displays the service availability status.

Please note that a modern version of the operating system is required for proper operation. On older versions of Android (below 8.0), this feature may not be available or may work unstable due to lack of support for the necessary security protocols. It is also important that your phone has the latest security updates.

A comprehensive guide to enabling VoWiFi

The process for activating this feature is standardized on most Android devices, although the menu item names may vary slightly. First, make sure Wi-Fi is enabled and your phone is connected to an internet connection. Without an active connection to the router, the option may be hidden or inactive.

Next, you need to go to the main device settings. Find the section responsible for connections. In stock Android, it's usually called Network and Internet, in Samsung shells - Connections, and in MIUI (Xiaomi) - SIM cards and mobile networksWithin this section, you should look for an item called "Wi-Fi Calling."

If you don't see the toggle immediately, try tapping the name of your SIM card if you have multiple. This feature is configured individually for each slot. After you activate the toggle, a phone icon with a Wi-Fi symbol or the word "VoWiFi" should appear in the status bar (notification shade).

In some cases, the system may request address verification for emergency services (E911). This is a standard procedure required by law in many countries to ensure emergency services can determine your location, even when calling online. This functionality is also being implemented in Russia, and it is not recommended to ignore the system's request.

⚠️ Note: After enabling this feature, your phone may reboot its network module. If the icon doesn't appear immediately, try turning Airplane Mode on and off or restarting your device.

It's worth noting that connection priority can be customized. Often, the options available are "Prefer Wi-Fi" (call only over Wi-Fi when available) or "Prefer Mobile Network" (use Wi-Fi only when there's no cellular signal). The choice depends on your needs and the coverage quality in your specific location.

Setting up Wi-Fi calling on Samsung

Samsung devices have one of the most sophisticated VoWiFi implementations in the One UI shell. The path to the settings here looks like this: open Settings, then go to ConnectionsIn this section you will see the item Wi-Fi callingIf it is not in the main menu, it may be located inside a subsection. Mobile network.

After activating the switch, the system will prompt you to select your preferred network type. For maximum performance, we recommend selecting "Prefer Wi-Fi." In this case, even if you have one or two bars of cellular service, your smartphone will attempt to connect the call over the wireless network, which often results in clearer sound.

Hidden Samsung Settings

Some Samsung models have an engineering menu where you can force VoWiFi to be enabled, but this can cause the phone to become unstable. Accessible by code. ##4636##, but it should only be used by experienced users.

An important nuance for Samsung owners is the dependence on the regional firmware version. If the phone was purchased from a "gray" importer, the feature may be blocked for local carriers. In this case, changing the CSC region code to the one where the phone is officially sold (for example, from Chinese to European) can help, but this requires specialized software on a PC.

Samsung smartphones also feature a "Smart Switch" feature that automatically switches active calls from Wi-Fi to the mobile network when you're away from the router. This ensures uninterrupted calls when you leave the house. Make sure this option is also enabled in your connection settings.

Activating the feature on Xiaomi, Redmi, and POCO smartphones

In the MIUI shell (and the new HyperOS), the settings logic is slightly different. Go to Settings, select SIM cards and mobile networksNext, click on the specific SIM card for which you want to set up calls. In the menu that opens, find the toggle Wi-Fi calling.

Xiaomi users often encounter a problem where the menu item simply isn't there, even though their carrier supports the technology. In this case, manually entering the code into the engineering menu helps. Enter the code in the dialer. ##869434##If everything goes well, you'll see a notification that says "VoWiFi carrier check was disabled," which means the feature is unlocked.

Once successfully activated, a corresponding icon will appear in the notification shade. On Xiaomi devices, it's also a good idea to check the power saving settings. Sometimes, aggressive power saving modes can kill the VoWiFi background process, leading to missed incoming calls. Add your phone to the exceptions list or select "Unrestricted" mode for system services.

Dual SIM modes are worth mentioning separately. On Xiaomi, when two SIM cards are active, VoWiFi may only work on one of them, usually the one set as the primary data card, or the first SIM. Check the phone's behavior with both numbers active.

Solution: Why VoWiFi isn't working

Even if all conditions are met, the function may not work. One of the most common reasons is a lack of carrier profile updates. Go to your SIM card settings and find "Update profiles" or "Update carrier settings." Tap the button and wait for the process to complete.

Another common issue is a conflict with VPN services. If you have a VPN enabled, your traffic may be routed through another region or country, and your carrier may block voice calls for security reasons or due to licensing restrictions. Try disabling your VPN and testing your calls.

⚠️ Note: Some routers have port or protocol blocking settings (SIP ALG), which can interfere with voice traffic. Try rebooting your router or temporarily disabling filtering.

It's also worth checking that "4G/LTE Only" isn't enabled in your network settings. Sometimes switching to "Auto" (2G/3G/4G) helps your phone register more correctly with the IMS network. Also, make sure you have sufficient funds in your account, as some carriers require a positive balance even for test service connections.

If all else fails, you can try resetting your network settings to factory defaults. This won't delete your personal data (photos, contacts), but it will return all network settings, including Wi-Fi passwords and Bluetooth settings, to their original state. Path: Settings → System → Reset → Reset Wi-Fi, mobile data, and Bluetooth.

Frequently Asked Questions (FAQ)

Do carriers charge extra for Wi-Fi calls?

Typically, there's no separate charge for VoWiFi technology itself. Minutes are deducted from your main plan plan just like regular minutes. However, if you're abroad, the rules may differ: some carriers count such calls as being made within your home region, which makes them preferable to roaming, but you should check the terms and conditions of your plan.

Does VoWiFi reduce sound quality?

On the contrary, with a good internet connection, the sound quality is often better than on a standard cellular network, thanks to the HD Voice codec. However, if the Wi-Fi channel is overloaded (for example, if someone is downloading torrents or watching 4K video), the sound may become choppy or robotic.

Is it possible to call emergency numbers (112) via Wi-Fi?

Technically, this is possible, but with some caveats. The accuracy of location determination when calling via Wi-Fi may be lower than via a cell tower, as the IP address is not always accurately linked to geolocation. Operators recommend using regular cellular service when possible to call emergency services.

Does VoWiFi work if Airplane mode is enabled on my phone?

Yes, this is one use case. If you enable Airplane Mode and then activate Wi-Fi, VoWiFi calls will work. This is ideal for using your phone as a landline in areas with no cellular service but Wi-Fi coverage.