Quick answer
Check likely coverage before switching by using Ofcom’s coverage checker, then rechecking the providers you are considering on their own coverage tools. Treat every checker as a planning signal rather than a guarantee for a specific room, street, commute or device.
Checks before you switch
- Test the postcode where the phone is used most often, not only the billing address.
- Compare indoor and outdoor results where a checker separates them.
- Check common travel locations such as work, school runs and family addresses.
- Recheck the provider site before ordering because checker data can lag local network changes.
- Keep a note of any weak-signal locations so you can compare them with the contract terms and cooling-off route.
Useful caveats
Coverage maps cannot prove that a phone will work everywhere. Building materials, congestion, device bands, weather, local works and network settings can all affect real use. If reliable coverage is critical, prioritise providers that let you test the service with low commitment before moving a main number.
What this guide does not cover
This guide does not rank networks, promise speed, confirm address-level serviceability or say that any provider is best. Use it as a pre-switch checklist alongside official and provider information.
Official sources to recheck
- Ofcom coverage checker.
- Ofcom switching mobile provider guidance.