Tuesday’s federal court ruling means Uber’s California drivers can, as a group, press the central claim of the case, that they can seek reimbursement for mileage and tips.

If the class action suit is indeed victorious, Uber could be on the hook for expenses, ranging from health insurance to workers’ compensation, and could even have to pay its drivers for fuel and toll costs.

In a separate case, California’s labor commissioner in June found that Uber treated one of its workers as an employee, forcing the taxi service to pay her the back wages she would have received as an employee.

In the ruling, U.S. District Judge Edward Chen in San Francisco said drivers could sue as a group on the question of whether they are employees or contractors, and over their demand for payment of tips that were not passed on to them.

The company considers the drivers who use its platform to be independent contractors.

Liss-Riordan said she didn’t yet know exactly how many drivers will be in the class but estimated the number as “many thousands”. The case could affect other big companies in the sharing economy.

Chen agreed that the content of each training session may have varied, but the argument “misses the point”. But any kind of forced changes to Uber’s business model could destroy that valuation, and be far-reaching. Uber will probably appeal the ruling because it is based on “several key legal errors”, Boutrous said.

In his ruling, Chen rejected Uber’s argument that there is no typical Uber driver so the named plaintiffs in the suit were not typical of their fellow class members.

Chen said the central issue was whether the drivers’ “relationships with Uber are sufficiently similar that a jury can resolve the Plaintiffs’ legal claims all at once”. The next step in the lawsuit would be that it is approved and more states, including California Uber drivers will be a complete part of the company, which will ultimately result in a huge financial damage for Uber. According to The Wall Street Journal, Judge Chen had excluded some of the drivers who work for independent transportation companies. In July, the company provided the court with 400 written declarations from drivers who say they prefer to be independent contractors because of this flexibility.

In other words, there was no way Uber could uniformly check that its drivers had showered so it couldn’t argue that its drivers were trained in different ways and couldn’t be part of a similar class.

While it’s convenient for customers, however, drivers involved in such services are not as happy about it. The lawsuit Uber drivers filed against the company claims that Uber should reimburse drivers for gas and various other expenses, basically re-designating from contractors to employees.