Transport for London is part way through a roll-out of 4G and 5G connectivity across the tube network and Elizabeth line.
By the end of 2024 — if timetables are met — you should be able to get a signal at any tube station and even in the running tunnels. It'll be a big step up from the, frankly, temperamental wi-fi signals that only work (sometimes) within tube stations.
You'll get a phone signal so long as you're on one of the four UK networks: EE, Vodafone, Three and VMO2. Your phone should automatically connect, and there is no extra charge.
We'll chart the progress of the rollout on the simplified map above.
September 2023: Oxford Circus and Tottenham Court Road are added, along with the Central line track between them. TfL also announces lots of imminent expansions, including the whole of the Elizabeth line, much more of the Northern line and parts of the Piccadilly.
June 2023: Mornington Crescent has been added to the network. The tunnels between Camden Town and MC should be kitted out soon.
May 2023: Camden Town has been added to the network. With the eastern stretches of the Jubilee line, and short sections of the Central and Northern lines, approximately 10% of subsurface stations now have access. Mornington Crescent, Oxford Circus and Tottenham Court Road are promised next.