Woman talking on the phone with a laptop whilst sitting on the sofa.

What is Wi-Fi calling? Exploring the latest evolution of telephone technology

By Andy Snellgrove | Date published: 1st March 2024 | 4 min read

On 10 March 1876, Alexander Bell yelled out in frustration. But irritation soon turned to delight as he realised the sound had been carried through the wire he’d laid. He’d made the first-ever phone call.

This technology went on to form our national telephone network. And, more than 150 years later, making calls has stayed key to how we keep in touch.

These days, however, our calls often take place over the internet using a variety of digital systems.

So, what is Wi-Fi calling?

Although Voice over Internet Protocol (VoIP) applications such as WhatsApp, Zoom and Google Meet can all be used to make calls while you’re connected to Wi-Fi, the term ‘Wi-Fi calling’ is usually used to refer to a different way of making calls.

Wi-Fi calling is a functionality built into the operating system of your mobile phone. This hidden magic, which you may not even know you have, allows you to use your mobile’s regular dialling screen and phone number to make and receive calls over Wi-Fi.

What are the pros of Wi-Fi calling?

Doesn’t need mobile signal

With Wi-Fi calling you can still make calls even if you’re in an area with unreliable mobile signal. All you need is a decent Wi-Fi connection, and you’re sorted.

No extra cost

Wi-Fi calls are usually charged like a normal call and either deducted from your relevant call allowances or charged at standard rates for the call type. So, as long as the Wi-Fi you access is free, there’s normally no extra cost. But, we suggest checking in with your service provider to ensure no extra or hidden costs.

Built-in

As Wi-Fi calling is built into your phone it works seamlessly with your existing number and contacts, and means you don’t need to worry about downloading, storing and logging in to other applications.

What are the cons of Wi-Fi calling?

Dependent on decent Wi-Fi

If the Wi-Fi network you’re connected to is slow or used by too many people, your call may suffer cut-outs. So, try to join a network powered by Full Fibre broadband, the most reliable broadband technology.

Not available on all phones

As Wi-Fi calling is still relatively new, not all mobile networks support it and some older phones don’t have the technology baked in. So you might need to switch or upgrade if you want to use it.

International restrictions

Many mobile networks won’t let you use Wi-Fi calling abroad, and those that do may charge you for roaming just like a normal overseas call. So be sure to check with your mobile network before banking on using it to make calls from far flung phone signal free locations.

Frequently asked questions

What is the difference between Wi-Fi calling and normal calling?

The real difference happens in the background. Wi-Fi calling involves routing the call through a Wi-Fi network rather than relying on your phone service provider's network.
How much does Wi-Fi calling cost and does it use data?

Wi-Fi calls don’t use mobile data and are usually charged like normal calls with the minutes deducted from relevant allowances, or charged at standard rates for the type of call you’re making.
What is VoIP?

Voice over Internet Protocol (VoIP) is a technology originally created to allow voice to be transmitted over the internet. To use it you usually need to download and log in to an app which may allocate you a new telephone number. Despite the name, these days VoIP apps usually offer more than just voice calls, including features like video calling, file sharing and instant messaging.
Can I use Wi-Fi calling overseas?

Whether or not you can make Wi-Fi calls when you're abroad depends on your mobile network’s policies. Some may restrict or charge for Wi-Fi calling while you're overseas so it’s worth checking in advance.

It will largely be dependent on the device itself. However, for both Android and iPhone, you should be able to turn it on or off by accessing the device settings. If you are struggling, you can always contact your service provider who could potentially help you with this.

Wi-Fi calls are usually charged like a normal call; either deducted from your relevant free call allowances or charged at standard rates for the call type. Of course, the Wi-Fi you use may charge to access it.

What is Wi-Fi calling good for?

Wi-Fi calling is great for situations where a standard phone signal isn’t available, but you still need to be able to receive and make calls from your usual phone number.
What is Wi-Fi calling not good for?

Wi-Fi calling isn’t great for making calls if your connection is poor. For the best chance of success, try using a Wi-Fi network powered by Full Fibre broadband, the fastest and most reliable broadband technology.

Written by Andy Snellgrove

Andy is the Openreach FTTP Product Manager and brings a wealth of experience in the broadband industry. With a strong background in launching FTTC, GFast, and most recently FTTP, he has collaborated with leading telecommunications companies to develop cutting-edge broadband capabilities.

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