Weak mobile signal? Let’s fix it
Answer a few questions and we’ll find why your mobile signal is weak — indoors only, everywhere, a local blackspot, or just your phone — and give you the exact fix. For most indoor problems the answer is Wi-Fi Calling, which routes calls over your broadband. It all runs in your browser.
Last updated: · Written by The NetSorted team
The most common causes of weak mobile signal
- Weak indoor signal. Thick walls and distance from the mast block signal. Wi-Fi Calling is the easiest fix.
- A local blackspot. Signal varies over a few metres — near a window or upstairs is usually stronger.
- Your handset or SIM. If only your phone is affected, restart it, reseat or replace the SIM, and update the software.
- A mast outage. If several phones are down, check your network’s status page.
- Poor coverage for your network. If everywhere is bad, another network may simply cover your area better.
Note on signal boosters: since 2018 Ofcom has allowed a limited range of licence-exempt mobile repeaters that meet its technical requirements, but non-compliant ones remain illegal to use. The simplest safe options are Wi-Fi Calling or a signal box (femtocell) from your own network.
Frequently asked questions
How do I fix weak mobile signal at home?
The easiest fix is Wi-Fi Calling: it routes calls and texts over your home broadband instead of the mobile network, so weak signal stops mattering indoors. Turn it on in your phone settings, and make sure your home Wi-Fi is strong where you make calls.
What is Wi-Fi Calling and should I turn it on?
Wi-Fi Calling lets your phone make normal calls and texts over a Wi-Fi network. It’s free on most UK networks and is the single best fix for poor indoor mobile signal — well worth switching on at home.
Why does only my phone have bad signal?
If other phones on the same network are fine, the problem is usually your handset or SIM. Restart the phone, reseat or replace the SIM, update its software, and try the SIM in another phone to see whether the fault follows the SIM or the handset.
Should I buy a mobile signal booster?
Some mobile repeaters are legal to use in the UK without a licence if they meet Ofcom’s technical requirements, but non-compliant ones remain illegal to use — so check Ofcom’s list before buying. The simplest, safe alternatives are Wi-Fi Calling, or a signal box (femtocell) provided by your own network, which uses your broadband to create a personal indoor signal.
Sources
- Ofcom — using a repeater to improve your indoor mobile phone signal — checked 14 June 2026