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How-to guide
Checking coverage properly before you commit
Coverage maps are predictions, not guarantees. Five steps that prevent most coverage regret.
Independence notice
Thirdgreenovo is an independent third-party information service. We are not affiliated with, authorised by, or acting for any network named on this page. Trade marks belong to their owners and identify the subject of guidance only. For account, billing or contract matters, contact your network's official customer service. Calls to our line are standard geographic rate and provide general guidance only.
The five-step check
- Official postcode checker of the physical network. For virtual networks, check the host — the mapping is in our virtual networks table.
- Ofcom's independent coverage checker. The regulator applies one standard across all four networks, cutting through marketing optimism.
- Indoor, not just outdoor. Most complaints arise indoors. Foil-backed insulation, low-E glazing and thick walls block signal; read the indoor prediction specifically.
- Trial before committing. A one-month or pay-as-you-go SIM (the host's own or any brand hosted on it) is the only test that reflects your exact rooms, commute and workplace.
- Enable Wi-Fi Calling on whatever network you choose as a permanent backstop for weak indoor spots — see Wi-Fi Calling explained.
Reading the results honestly
- Judge a network by the layer you will actually use — if the checker shows 4G only at home, 5G speed claims elsewhere are irrelevant to you.
- "Variable" indoor predictions usually mean exactly that: fine by the window, poor in the back room.
- New masts and mast upgrades change positions over time — recheck before assuming last year's answer still holds.