Europe's highest court has ruled Uber is a taxi service and not just a ride-hailing app, meaning it can be regulated.
The decision is expected to have a major impact on how the firm is handled by European governments.
The case was brought by a Spanish taxi drivers' association.
The European Court of Justice found that the app is an 'intermediation service' and is 'inherently linked to a transport service'.
In a press release, the court explains: "The application provided by Uber is indispensable for both the drivers and the persons who wish to make an urban journey. [The Court] also points out that Uber exercises decisive influence over the conditions under which the drivers provide their service.
"Therefore, the Court finds that that intermediation service must be regarded as forming an integral part of an overall service whose main component is a transport service and, accordingly, must be classified not as ‘an information society service’ but as ‘a service in the field of transport’".
Uber has faced various regulatory hurdles in its bid to expand - both in Europe and elsewhere.
In Dublin, the company cannot offer private cars or 'ride sharing' as it does in other areas - meaning the app here can only be used to hire traditional taxis or limousines.
Additional reporting by IRN