What is VoLTE?
VoLTE stands for Voice over LTE (Long-Term Evolution — the technical name for 4G). It's a standard that allows voice calls to be transmitted entirely over the 4G data network, rather than requiring a separate 2G or 3G circuit for voice.
Before VoLTE, your phone would silently drop from 4G to 3G or 2G every time you made a call. You may have noticed your data connection pausing at the start of a call — that was the 3G handover happening. VoLTE eliminates this. Calls connect faster (typically under a second), sound better (HD audio, 8 kHz vs 3.4 kHz frequency range), and your data connection stays active during a call.
Since all four UK networks completed their 3G switch-off, VoLTE is now a requirement — without it, your phone can only make calls over 2G where available, or not at all. See our 3G switch-off guide for more on this transition.
What is Wi-Fi calling?
Wi-Fi calling routes voice calls and SMS messages over your broadband connection instead of the mobile network. It's activated on your phone independently of VoLTE and works even when you have no mobile signal at all — as long as you have Wi-Fi.
For anyone with consistently poor indoor mobile signal, Wi-Fi calling is the single most impactful free improvement available. You can be in a basement with zero bars and still receive calls to your normal number via Wi-Fi calling.
How to enable them
iPhone: Settings → Phone → Wi-Fi Calling (toggle on). VoLTE is enabled at Settings → Mobile Data → Mobile Data Options → Voice & Data → set to LTE or 5G.
Android: Phone app → Settings (three dots or gear icon) → Calls → Wi-Fi Calling. VoLTE is usually under Settings → Network & Internet → Mobile Network → Enhanced 4G LTE Mode (or similar — varies by manufacturer).
Both features require your network to have enabled them on your account, which is automatic for most UK plans. If the options don't appear, contact your network.