Fines imposed against owners renting their Paris apartments out on Airbnb surged more than tenfold in the first half of 2017 thanks to more rigorous monitoring, city authorities said on Friday.
Thirty-one owners of 128 units were slapped with a total of 615,000 euros ($723,000) in fines for renting them out for more than the city limit of 120 days per year, city hall official Ian Brossat said.
"These numbers do not reflect an explosion in the number of rental offers but in the effectiveness of the monitoring" by a team of 25 agents deployed by the city, Brossat said.
"We are pleased to see that the courts have a heavier hand than before," he added.
The maximum fine for the offence doubled in November to 50,000 euros.
Paris is one of Airbnb's top markets, with some 65,000 sites listed. Another 35,000 are available from similar online platforms.
The city has slapped limits on the short-term rental of apartments and rooms as they compete with hotels, encourage property speculation and reduce the housing available to residents.
The practice of rentals on Airbnb and rival websites has become so pervasive that some neighbourhoods have nearly emptied of permanent residents.
"You can't turn your lodging into a cash machine and yourself into a speculator," Brossat told French radio France Inter.
Airbnb meanwhile said the fines "are far from being representative of the Airbnb community in Paris, where the average host rents out their lodgings 33 times per year."
Airbnb warns homeowners on its website they must comply with local laws, and said it had proposed a solution last year to the city which would have automatically limited rentals to 120 nights per year.
"This would have simplified monitoring without stigmatising the large majority of hosts who abide by the rules and count on Airbnb to make sure the ends meet at the end of the month," it said in a statement.
France also wants to address a tax situation that allows Airbnb to avoid paying French taxes on rentals in France.
Since bookings and payments on French rentals are run through the group's European headquarters in Ireland, it escapes paying taxes on those to the French treasury.
The Paris daily Le Parisien reported Monday that Airbnb paid less than 100,000 euros in French taxes last year when more than 10 million French people used the site.
On Wednesday, French Economy Minister Bruno Le Maire said France would team up with Germany to address the loophole because efforts by the EU Commission and the OECD were "taking too much time".
Le Maire said Paris and Berlin would come up with a joint plan to fix the situation -- also going after online platforms like Google, Amazon and Facebook -- by mid-September.
"Airbnb has the right to operate in France. But we have the right to demand from Airbnb and all the other digital platforms a fair contribution to the French treasury," Le Maire said.