A ruling by the European Court of Justice (ECJ) that Uber should be regulated as a transport company will not affect its operation "in most EU countries", the firm has said.
Uber had argued it was a technology service enabling people to contact each other, rather than a cab firm.
But the ECJ, based in Luxembourg, found that it "must be regarded as forming an integral part of an overall service whose main component is a transport service".
The case stemmed from a complaint by Barcelona taxi drivers who claimed Uber drivers should be licensed.
While the ruling could change the way Uber operates in some European cities, the company insisted there will be no impact in most countries.
An Uber spokesman said: "This ruling will not change things in most EU countries where we already operate under transportation law."
The verdict comes after Transport for London (TfL) refused to renew Uber’s operating licence in the UK capital in September on the grounds of "public safety and security implications".