What a coverage map really shows, why one room behaves differently from the rest, how congestion differs from weak signal, and the only evidence that settles your own address.
Written July 2026 · no prices published · nothing for sale
Every coverage map is a computer model of predicted signal outside buildings, calculated from terrain, mast locations and transmit power. It is a good first filter and a poor conclusion.
A headline such as "99% population coverage" describes people, outdoors — not land, and certainly not your kitchen. Run the network's own checker and Ofcom's together, weigh the indoor figures, and where they disagree, test rather than guess.
Modern insulation, thick stone and metallised glass all block radio. This is physics rather than a fault, and no amount of complaining changes it.
| Remedy | What it does |
|---|---|
| Wi-Fi Calling | Routes calls over your home broadband so walls stop mattering — free on every major network |
| 4G Calling | Required for voice now that 3G has been switched off nationally |
| Moving a metre | Toward a window changes reception measurably |
| Independent repeaters | Can interfere with the network — ask your provider what it offers instead |
Full signal bars with nothing loading is not weak reception at all — it is too many handsets sharing one mast. It clusters around transport hubs, venues and city centres in the early evening.
This matters because switching network cures a coverage problem but may do nothing for a congestion one. If the alternative is equally busy at the same spot at the same hour, you will have moved for nothing.
| Network to test | Cheapest way to test it |
|---|---|
| O2 | giffgaff or Tesco Mobile |
| Three | SMARTY or iD Mobile |
| EE | 1pMobile |
| Vodafone | VOXI or Lebara |
Live on the test SIM through a normal week — home, work, the commute, the supermarket queue — and include your commuting point at rush hour. Re-run the check once a year, because masts are built and re-tuned constantly and two national estates are currently merging.
Ring us and we will go through it with you. Nothing is offered for sale at any point.
We hold no arrangement with any network, take no commission and sell nothing at all. If your question is not answered here, telephone and ask.
How we are placed. thurlowvance is an independent information service for mobile customers in the United Kingdom. We are not a mobile network. We have no affiliation with, endorsement from, appointment by or connection to Three, EE, O2, Vodafone, Sky Mobile, Tesco Mobile or any other provider, and no commercial arrangement with any of them. We do not sell, supply, arrange or broker SIM cards, contracts, handsets or services of any kind, and we take no commission from anybody. Everything here is general information; a provider's own current terms always take precedence.
© thurlowvance. Network names belong to their owners and appear only to identify the services described.