London’s mobile networks fall to bottom of Europe’s capital league

London's mobile network performance has slipped behind other European capitals as operators struggle to add capacity fast enough to meet demand.

The city ranked seventh out of 18 in the continent for median download speed in 2021, but traffic has since expanded faster than available capacity. Other metropolises have improved; London now has the slowest speeds and the highest latency under load, according to mobile network testing firm Ookla.

The research points to obstacles mobile operators face in adding extra capacity: applications for new street masts in London have fallen since 2022, and about three quarters of those filed since 2019 were refused.

The Big Smoke was among the first European capitals to get 5G coverage, yet when Ookla's Q3 2026 tests found the city now has the slowest median download speed (109.43 Mbps), the slowest median upload speed (11.40 Mbps) and the highest latency under load - a measure of how the network copes with heavy use.

Ookla's records show London’s 5G medina speed peaked at 200 Mbps in Q2 2021, fell as low as 102 Mbps in Q3 2023, then recovered slightly. Paris, by contrast, has stayed above 225 Mbps since mid-2021.

The cause is congestion. In Central London, performance slumps on weekdays as commuters arrive: median download speed falls to 80.07 Mbps through the morning, 27 percent below weekend levels at the same hours.

Part of the problem is that UK mobile operators own few of their antenna sites, many of which sit on rooftops in built-up areas, says Ookla.

Under the Electronic Communications Code, and changes introduced in 2017, a London rooftop is worth about £1,000 ($1,333) a year to its owner, down from £21,000 ($28k). That givers landlords little motivation to host antennas, and many prefer solar panels.

Operators can also receive notices to quit when a building is redeveloped, and it is estimated that this keeps about 7 percent of London’s rooftop sites out of action at any time.

Planning rules compound the problem as applications for new masts are more likely to be refused in boroughs with conservation areas, such as Westminster. Street mast applications peaked in 2020, early in the first 5G build, and have fallen by more than four-fifths since 2022. Three quarters of applications for new street masts since 2019 were refused, against one in five upgrades.

"Planning restrictions, particularly in conservation areas, make it harder to install and upgrade the mobile equipment London needs," Ookla lead industry analyst Luke Kehoe told The Register.

"Notices to quit can also force rooftop sites offline during redevelopment long before replacements are ready, leaving operators trying to restore lost capacity while demand keeps growing."

City Hall has noticed, and a draft plan for the capital drawn up by the Mayor of London observes that notices to quit "have eroded London’s overall mobile connectivity compared to other equivalent cities."

The plan, due tor adoption in 2028, would require developers to keep mobile service running during construction, put masts on taller buildings and in the public realm; and ask boroughs to work with operators on sites in conservation areas.

Other experts blame different factors for London’s poor mobile service. Professor Mohamed-Slim Alouini of the King Abdullah University of Science and Technology (KAUST) told The Register last year that the government’s decision to rip-and-replace network equipment supplied by China-based vendor Huawei had diverted funds that should have gone into building more capacity.

He also said 5G was overhyped early on, leading to a perception among users that it wasn’t really worth having and operators reluctant to invest.

Whatever the cause, London’s mobile experience now trails its European peers, though people elsewhere in the UK who still can’t get a 5G signal will have little sympathy. ®