# UK not-spots — methodology

Number and percentage of homes with **no fixed broadband** and/or **no mobile coverage**, per UK Westminster constituency (650) and local authority (361), so "double not-spots" (cut off from both) can be identified.

**Source.** Ofcom Connected Nations, January 2026 (reference date 1 January 2026). Crown copyright, used under the Open Government Licence v3.0. Joined to mobile data on ONS GSS codes.

**Broadband.** Ofcom's "premises unable to receive decent broadband from fixed or fixed-wireless access" (the Universal Service Obligation threshold).

**Mobile.** Premises with **no coverage from any of the four UK operators** (EE/O2/Three/Vodafone), reported three ways: no 4G indoors, no indoor voice call, no 4G outdoors.

**Framing.** These are **homes within each area** that lack coverage, ranked by area — not areas with 0% coverage everywhere.

**Derived column.** `both_score_pct` = the lower of broadband no-decent % and mobile no-indoor-4G %, so an area only scores high when it is hit on BOTH counts (a broadband-fine but mobile-bad area scores low). Rows are ranked by it. A Switchity convenience, not an official Ofcom figure.

Prepared by Switchity — https://switchity.co.uk/mobile-coverage/