More than 1,700 Boston listings were removed from Airbnb in December, after the short-term rental company began dropping unregistered units as part of an agreement with the city.

Airbnb agreed to boot listings that weren't registered with the city by Dec. 1 (City rules require all short-term rentals to be registered). The agreement — which bolstered the city's efforts to crack down on illegal listings — was reached after the company sued over Boston's 2018 short-term rental ordinance.

Following the agreement, the number of Airbnb listings went from 5,500 in November to 3,780 in December — a 31% decrease — according to the city of Boston.

The 1,720 listings that were removed were either unregistered or ineligible units, or in some cases old listings, according to Boston's assistant housing commissioner Claudia Correa.

"They have been working on keeping their part of the bargain in regards to the agreement," Correa said of Airbnb.

In a statement, Airbnb's head of mid-Atlantic policy Kelley Gossett said the removal of listings is "proof of our long-term commitment to collaboration with the City. Going forward, we will continue to work with the City to take the appropriate action against listings, as needed.”

The ordinance applies to other short-term rental companies too, but some have continued to list ineligible units, according to Correa.

"If we come across a platform that is listing any non-qualifying short-term rental, we are issuing fines to them," Correa said.

Boston has issued 367 fines totaling $90,200 since the short-term rental ordinance went into effect last year, according to the city. The fines vary from $100 (for failure to register) to $300 (for listing ineligible rentals). Most of the fines were issued to owners who didn't register their units.

About 10% of the fines were issued to companies for listing ineligible units. Companies that have been fined include Churchill Living, Global Luxury Suites, Sonder and Boston-based Flipkey, which is owned by TripAdvisor, according to the city. Some companies are appealing the fines.

"Sonder respects and adheres to all local laws in Boston - our portfolio in the City is fully licensed, or currently being licensed as executive suites for visitor use," a company spokesperson said in a statement. "We fully expect any fines to be resolved in the process."

Correa said the city is working to ensure all short-term rental companies are removing illegal listings.