In a statement emailed to NBC News, Uber called the decision "extraordinary and wrong."
LONDON - London's transit authority said Monday it would not renew Uber's license to operate in the British capital over passenger safety concerns.
Transport for London cited "several breaches that placed passengers and their safety at risk."
A key issue identified was that a change to the ride-hailing company's systems allowed unauthorized drivers to upload their photos to other Uber driver accounts.
"This allowed them to pick up passengers as though they were the booked driver, which occurred in at least 14,000 trips, putting passenger safety and security at risk," the transport authority said.
This means all the journeys were uninsured and some passenger journeys took place with unlicensed drivers, Transport of London said.
Another failure allowed dismissed or suspended drivers to create an Uber account and carry passengers. As a result, it has deemed Uber "not fit and proper at this time."
In an emailed statement to NBC News, Uber called the decision "extraordinary and wrong."
It promised to appeal the decision and operate "as normal" in London while the appeal process is underway.
The company also said that it has audited every driver in London over the last two months and will soon be introducing a new facial matching process for drivers.
London Mayor Sadiq Khan tweeted to say that he supports the decision, adding that he welcomes technical innovation in the city, but companies have to "play by the rules" to keep customers safe.
Transport for London had already been keeping Uber on an increasingly tight leash. It had renewed Uber's license for only two months in September and imposed stricter conditions following concerns about aggressive corporate tactics and passenger safety.