Dutch authorities on Tuesday said they have raised the amount they can fine UberPOP to one million euros ($1,12 million) after the taxi service paid out the previous maximum of 100,000 euros.
"We have raised the fine ceiling for UberPOP: each time a driver is arrested, the maximum fine will be 50,000 euros," Elif Bagci, spokeswoman fot the Dutch Transport and Environment authority, told AFP.
"If they continue, Uber will have to pay a maximum of one million euros," she said, adding that Uber had already paid 100,000 euros in fines.
Dutch judges in December banned UberPOP from taking bookings via its smartphone app, threatening the US company with fines of up to 100,000 euros.
Uber said it would contest the ruling and has continued to offer UberPOP.
Uber uses mobile phone apps to put customers in touch with drivers who then take them where they want to go, at prices lower than those of traditional taxis.
But despite its growing popularity, Uber is facing increasing limits on its activities in EU countries and a barrage of legal challenges spurred on by a furious taxi lobby, who say Uber drivers should be regulated the same way as normal cabs.
UberPOP, which lets private car drivers offer taxi services, said last month that it would help its drivers obtain taxi licences.