Thousands of Airbnb listings may drop off the home-sharing market as enforcement of NYC's short-term rental registration rules takes effect today, some because they are no longer eligible—but others because the city is far behind on processing a surge in applications from hosts.

Last month, a state Supreme Court judge dismissed Airbnb's lawsuit seeking an injection to block New York City's registration rules for short-term rentals, which requires Airbnb hosts to register with a database overseen by the Mayor's Office of Special Enforcement (OSE).

OSE now is struggling to keep up with a surging backlog of registration applications required by Local Law 18. According to Skift, a travel publication, OSE so far has approved only 257 short-term rental host registrations out of 3,250 applications, Bloomberg reported.