While it may seem like there is "no Wi-Fi" while moving through the tunnels, Transport for London (TfL) has actually installed Wi-Fi at more than 260 London Underground stations. The "lack" of Wi-Fi specifically refers to the deep-level tunnels between stations, where the thick clay and Victorian-era infrastructure make traditional signal propagation difficult and expensive. However, as of 2026, this is rapidly changing. TfL is currently rolling out uninterrupted 4G and 5G mobile coverage across the entire network, including within the tunnels themselves. Many sections of the Jubilee, Central, and Elizabeth lines already offer full connectivity. The primary reason for the historical absence of tunnel Wi-Fi was the technical challenge of installing "leaky feeder" cables and base stations in a 24-hour environment with very limited maintenance windows. For now, if you lose connection, your phone will typically re-sync automatically at the next station platform, but soon, "tunnel dead zones" will be a thing of the past.