qukbnaro Readers' questions about UK mobile · Postbag 08
Postbag 08

Why does the coverage map lie?

Answered 17 June 2026 · reading time about 3 minutes

“The map says excellent signal at my address. I get one bar in the kitchen and none upstairs. Who do I complain to?”

— M.F., Halifax
Man using a smartphone by a window
Photo from a free stock library, used for illustration only.
Important notice: qukbnaro is an independent reader-question blog. We are not a mobile network, and we are not affiliated with, endorsed by or connected to Three, O2, Sky Mobile, EE, Vodafone or any other provider. We do not sell SIM cards, contracts, handsets or services. Every answer is general guidance only — confirm current details with the provider's own website or app before deciding anything.
The short answerBecause coverage maps are computer predictions of outdoor signal, and you live indoors. Run two checkers, weight the indoor figures, then buy one cheap month and find out for certain.

Every network publishes a map generated by modelling — terrain, mast positions, transmit power. What no model can capture is your walls, your neighbours' walls, and how many people share your local mast at six in the evening.

Step one

Run two checkers, not one

The network's own postcode checker and Ofcom's independent one. Where they agree, believe them. Where they disagree, the trial month decides.

Step two

Weight indoor predictions heaviest

Indoors is where you live and where every network is weakest. An address that looks excellent outdoors can be hopeless in a back bedroom.

Step three

Buy one rolling month

Use the budget tenant on the same masts. Live on it for a full ordinary week — home, work, commute, the supermarket queue — and test the rooms that actually matter.

Step four

Re-run it every year

Masts get built, upgraded and re-farmed constantly, and the VodafoneThree merger is redrawing the map right now. An address that failed last year can pass this year.

Reader beware: Moving house? Run the checks on the new postcode before you exchange. Signal is far easier to verify than to fix.
Important notice: qukbnaro is an independent reader-question blog. We are not a mobile network, and we are not affiliated with, endorsed by or connected to Three, O2, Sky Mobile, EE, Vodafone or any other provider. We do not sell SIM cards, contracts, handsets or services. Every answer is general guidance only — confirm current details with the provider's own website or app before deciding anything.

Got a question of your own?

We answer readers, not customers. Nothing here is for sale, we can't see your account, and we will never ask for a security code.

020 3475 9516WhatsApp

This site sets one essential cookie plus anonymous visit counts — see the cookie policy.