Mobile signal on parts of London's Underground now matches or beats street-level coverage for 5G, according to analysis by network intelligence firm Ookla, as Transport for London continues connecting the network after missing a 2024 deadline. The rollout matters because it addresses a long-standing gap in mobile connectivity for millions of daily Tube passengers, and the finding that below-ground infrastructure can rival surface coverage is notable given the difficulty of retrofitting Victorian-era tunnels with modern telecoms equipment.

Ookla's analysis of over 50 million signal scans across Greater London found 19.8% of below-ground connections used 5G, compared with 16.5% above ground citywide, with stronger median signal strength recorded underground for both 4G and 5G. However, Ookla cautioned this citywide comparison flatters the Tube, since it runs beneath central London where surface coverage is strongest; a like-for-like comparison with streets directly above stations showed the surface still leading slightly. About 60% of below-ground stations currently have coverage, provided by neutral host Boldyn Networks (formerly BAI Communications), with full network connectivity expected by the end of 2026.