Modern smartphones offer many features that significantly improve the quality of communication, and one of the most useful is VoWiFiOwners of the popular model Samsung Galaxy A12 People often wonder how to activate this mode to make calls over a wireless network when the cellular signal is weak or absent. This technology routes voice calls over an internet connection, providing crystal-clear sound and stability in areas where traditional base stations fail.
To activate this option on your device, you do not need to install any third-party applications, as the functionality is built into the system. Android and the shell One UIHowever, the process may differ depending on the regional firmware version and your mobile operator's settings. In this article, we'll cover all the details, check compatibility, and learn how to bypass potential system limitations.
Before proceeding with the settings, it is important to make sure that your tariff plan and SIM card support this service. The VoWiFi feature is free from the operator, but traffic may be consumed according to your tariff plan, unless otherwise specified. Let's look at how to prepare your device for high-quality communication.
Checking operator support and tariff
The first and most important step is to verify the possibility of use Wi-Fi Calling Your mobile operator. Not all mobile operators support this technology on all plans, and the list of supported companies is constantly changing. If your provider hasn't enabled this feature at the network level, the settings on your phone may be hidden or inactive.
It often happens that the phone is technically Samsung A12 It's fully operational, but the operator requires you to submit an application or activate the service through your personal account. In some cases, the service is activated automatically upon first use, but it's best to check this beforehand to avoid disappointment.
- 📱 Contact your carrier's technical support or check the information on the official website.
- 💳 Make sure your SIM card is not too old and supports modern 4G/LTE communication standards.
- 🌍 Check if you are in roaming, where the service may be unavailable or expensive.
It's worth keeping in mind that even if a carrier claims support, coverage may be limited in some regions. It's also important that the address you provide during registration (for emergency services) matches your actual location, although this aspect is still less strictly regulated in our country than in Western countries.
Activating the function in the standard menu
If you have verified that your operator provides the service VoWiFi, you can start setting up the smartphone itself Galaxy A12In most cases, activation occurs through the standard settings menu, which is intuitive for any user.Settings → Connections → Wi-Fi Calling.
The algorithm of actions may vary depending on the version of the operating system and the specific modification of the device.
Once you enter the menu, you'll be asked to accept the terms of service. This is a standard procedure that describes how location data is shared with emergency services. Once accepted, the feature slider will become active, and a corresponding icon will appear at the top of the screen next to the Wi-Fi indicator.
☑️ Activation checklist
Sometimes users encounter a situation where the menu item is present, but inactive (grayed out). This almost always means the phone doesn't have a SIM card from a supported carrier, or it's installed in the secondary SIM card slot, which isn't a priority for voice calls. Move the SIM card to the primary slot and reboot the device.
⚠️ Attention: If the icon doesn't appear after activation, try switching the network mode. Go to
Settings → Connections → Mobile networks → Network modeand selectLTE/3G/2G (auto)Sometimes, forcing 4G on helps the system register the VoWiFi service.
Hidden settings via the engineering menu
In some cases, especially on devices purchased from unauthorized retailers or imported from other countries, the standard activation path may be blocked by the manufacturer or carrier. This is where the engineering menu comes in handy. Samsung, which allows access to hidden diagnostic and configuration functions.
To enter this menu, a special code is used that works on most devices. AndroidYou need to open the "Phone" app and enter the required character combination. Be careful when changing unknown parameters, as this may affect the radio module's stability.
*#27663368378#After entering the code, a menu will open Engineering ModeFind the item related to VoWiFi or IMS (IP Multimedia Subsystem). The IMS subsystem is responsible for multimedia services, including voice calls over LTE and Wi-Fi. You need to find the switch Wi-Fi Calling and set it in position Enabled.
- 🔍 Look for tabs named "IMS Settings", "Voice over WiFi" or "RRC".
- 🔄 After changing the settings, be sure to perform a full reboot of your smartphone.
- ⚙️ If the code doesn't work, try the alternative:
##4636##(does not work on all Samsung firmware versions).
Please note that intervention in the engineering menu may be reset after a firmware update. If you have updated One UI to the new version, the procedure may have to be repeated. Also, some operators have learned to detect such manipulations and may block the service on the network side.
What to do if the code doesn't work?
If the standard codes don't open the menu, your firmware version may be limited. Try installing the "Samsung Good Lock" app from the Galaxy Store and the "RegiStar" module, which can sometimes unlock additional interface features, although it's difficult to access IMS directly.
Setting up via the operator's application
Large mobile operators often develop their own applications for managing services, and it is through them that it is sometimes easiest to activate Wi-Fi Calling on Samsung A12This is especially relevant if the desired option is missing or hidden in the phone's system settings.
The logic behind these apps is simple: they send a special USSD request or push command to the operator's server, which then forcibly activates the service for your number. Afterward, your phone may require a reboot, after which the feature becomes available even without extensive menu settings.
| Operator | Application name | Section for settings | A reboot is required |
|---|---|---|---|
| MTS | MTS Russia | Services / Calls | Yes |
| Beeline | My Beeline | Services / Main | Yes |
| Megaphone | Megaphone | Services / Communication | No (often) |
| Tele2 | My Tele2 | Services / Options | Yes |
After activating through the app, don't forget to check your phone's settings. Sometimes the app only enables the service on the network side, but doesn't change the priorities on the smartphone. You may still need to go to Settings → Connections and make sure the toggle switch is on.
Conflict resolution
Even with proper configuration, users Samsung A12 You may encounter problems: calls are dropped, the sound quality is poor, or the icon keeps disappearing. Often, the cause lies in conflicting power saving settings. Android aggressively saves battery power and can disable background processes needed to maintain a VoWiFi connection.
You need to add your phone service to the power saving mode exceptions. Go to Settings → Device Maintenance → Battery → Background Battery UseFind "Phone," "IMS Service," or "Wi-Fi Calling" in the list of apps and select "Unlimited."
⚠️ Attention: An unstable Wi-Fi router can also cause call drops. If the router frequently changes channels or reboots, the phone will switch to the mobile network, which can lead to connection drops unless Seamless Handover is configured.
Another common issue is VPN use. If you have a VPN enabled, your voice call traffic may be rerouted through foreign servers, which your carrier interprets as roaming or suspicious activity. For a stable connection VoWiFi It's better to turn off the VPN during a call.
- 🚫 Disable "Data Saver" mode in the Wi-Fi network settings you're connected to.
- 📡 Make sure your Wi-Fi signal is strong enough (at least 2-3 bars), otherwise your phone will constantly switch between networks.
- 🔄 Reset network settings (
Settings → General Settings → Reset → Reset Network Settings), if the problem is systemic.
Differences in One UI interfaces
Interface Samsung One UI is updated regularly, and the arrangement of elements may change. Samsung A12 Depending on the year of manufacture and region, different versions of Android (11, 12, 13) may be installed. In newer versions of the shell, Samsung strives to simplify the menu, hiding technical details.
In recent updates, the settings menu has often moved to the quick access menu. If you can't find the feature in the deep settings, try pulling down the notification shade twice and looking for the button. Wi-Fi Calling among the icons. If it's not there, click the three dots or the edit button (plus/minus) at the end of the list to add it to the panel.
It's also worth mentioning the difference between the "Prefer Wi-Fi" and "Prefer Mobile Network" modes. Some firmware versions offer a third option, "Wi-Fi Only," which completely disables the cellular network for calls while connected to the router. This is useful in areas with very poor cellular coverage but good internet access at home.
The impact of roaming and international travel
One of the most useful use cases Wi-Fi Calling on Samsung A12 While roaming, you can connect to Wi-Fi at a hotel or café and call Russian numbers at your home network rates, avoiding hefty roaming bills for incoming and outgoing calls.
However, there's an important caveat: your phone must register with the foreign network at least minimally to recognize it's roaming and activate the appropriate profile. Therefore, don't set your Wi-Fi to "Flight Only" immediately upon arrival. Let your phone find a local network, wait for the roaming welcome SMS, and only then switch to a Wi-Fi zone for calls.
Always check the current terms and conditions before traveling, as some operators require explicit consent to use the service abroad.
⚠️ Attention: When making calls over Wi-Fi while roaming, your number is identified as the local number of your operator's country. For emergency services (112, 911) in another country, a Wi-Fi call may fail or connect to a service that's not geographically closest to you.
Frequently Asked Questions (FAQ)
Do you charge per minute for Wi-Fi calls?
VoWiFi technology itself is free. Minutes are deducted from your basic plan plan just like regular calls. However, if you're roaming internationally, the rules may differ, and the call may be charged as a domestic call. This is advantageous, but you should check with your carrier.
Why does the Wi-Fi Calling icon appear and disappear?
This occurs when the Wi-Fi signal quality drops below a certain threshold, and the phone automatically switches to the mobile network to maintain connection quality. It can also be caused by aggressive power saving, which puts the Wi-Fi module to sleep when idle.
Is it possible to make calls via Wi-Fi if the SIM card is not detected?
No, VoWiFi requires an active SIM card in your phone, even if the call itself is made over the internet. The phone uses the SIM card's data to authenticate with the operator's network (IMS).
Does this feature work if there is no mobile network at all (Airplane mode)?
Yes, if allowed in the settings. You can enable airplane mode, then activate Wi-Fi separately. If the service is configured correctly, the VoWiFi icon will appear, and calls will be received. This is ideal for underground parking lots or buildings with thick walls.
Does VoWiFi reduce sound quality compared to regular communication?
Conversely, with a good internet connection, the sound quality is significantly higher (HD Voice). However, with a poor internet connection (low speed, high ping), the sound may become choppy or robotic, while a standard GSM connection would simply be quieter but more stable.