Transport for London says coverage has also been expanded in the tunnelled section between Balham and South Wimbledon.
Kennington, Oval, Tooting Broadway and South Wimbledon stations also have better mobile access.
The mayor of London originally promised passengers would have full mobile coverage across the network by last year.
But that was then pushed back until at least 2026.
The Deputy Mayor for Transport, Seb Dance, said: “The introduction of 4G and 5G along further stretches of the Northern, Piccadilly and Victoria line means even more Londoners will now be able to stay connected on the Underground, reading, streaming or catching up with loved ones. This is yet another step towards delivering the Mayor’s commitment to rolling out 4G and 5G across the whole Tube network, building a better London for everyone.”
Rebecca Bissell, Director of Technology Product and Operations at TfL, said: “It’s great that these new sections of the Tube, in particular in south London and the first sections of the Northern line which serve the City of London, are starting to get mobile coverage. We are committed to bringing high-speed 4G and 5G mobile coverage to the whole of the Tube network, allowing our customers to stay connected while travelling to work, shopping or socialising. Further tunnelled sections will be going live in the coming months and we are working hard to bring the benefits of being able to stay in contact while travelling through our city as quickly as possible to the rest of the network.”
