Uber faced stricter regulation in Europe after the EU’s highest court ruled it is officially a taxi service and not a technology company.

In a statement, the European Court of Justice (ECJ) announced Uber “must be regarded as being inherently linked to a transport service and, accordingly, must be classified as a service in the field of transport”.

The issue arose after Uber was ordered to abide by local taxi rules in Barcelona following a complaint by a professional drivers’ association. The body argued Uber’s action in Spain was leading to unfair competition because the company was using drivers without commercial licences.

Uber since argued it operates as an “information society service”, allowing people to communicate with one another electronically.

While the ECJ ruling is not legally binding, the decision means Uber can now be regulated as a transport company and, thus, rules against it can be set at country level in the EU’s 28 member states. Digital platforms, in contrast, are subject to regulation at a wider European level.

The ECJ had previously stated Uber was more than an intermediary for customers seeking a taxi despite its use of mobile technology.

An Uber representative said the decision would not impact its business in most EU countries “where we already operate under transportation law”, but said it could impact “millions of Europeans” by restricting access to the taxi-booking app.

While the company maintains it complies with relevant laws in markets including France, the UK and Germany, the company is currently appealing a decision by Transport for London to deny it a new private hire operating licence.