A group of Uber drivers are entitled to worker rights.
The ruling on Friday (Feb 19) from Britain's Supreme Court means some workers will be able to claim rights such as the minimum wage.
In a case led by two former Uber drivers, a London tribunal ruled in 2016 that they were due entitlements, including paid holidays and rest breaks.
Uber drivers are currently treated as self-employed, meaning that by law they only get minimal protections.
That's a status the Silicon Valley-based company sought to maintain in the long-running legal tussle.
A judge in the appeal said on Friday that "the Supreme Court unanimously dismisses Uber's appeal".
A total of 25 drivers were part of the case, and Uber said the verdict did not apply to all of its current 60,000 drivers in Britain.
It has around 45,000 in London alone, making the city one of the ride hailing app's most important global markets.
Uber's Northern and Eastern Europe boss said after the news that the company is "committed to doing more".
Adding that it "will now consult with every active driver across the UK to understand the changes they want to see."
Uber shares fell over 3% in premarket trading following the court announcement.
The ruling is a blow to the app and its model within the so called gig economy, where people tend to work for one or more companies on a job-by-job basis.
That system has faced criticism from trade unions who say it is exploitative.
Businesses though say many of those working in the gig economy enjoy the flexibility.