UPDATE (Thursday, Sept. 5, 8:35 a.m.) – Portland officials have reached a landmark agreement with one of the largest online vacation rental platforms, Airbnb, that will make it easier to remove listings that violate Portland regulations.

Airbnb has agreed to share data with regulators about the listings posted on its site and pay the city a small annual fee to facilitate data sharing and enforcement.

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The deal follows years of negotiations – and legal action – between the city and the company.

After becoming the first city to formally legalize short-term rentals, Portland has struggled to enforce the permitting rules it laid out that were intended to limit the impact of vacation rentals on the housing market as the cost of housing steadily increased.

Related: Portland Drafts Ordinance To Crackdown On Airbnb

The agreement with Airbnb follows a federal appeals court ruling in March that dealt a blow to the internet-freedom argument that Airbnb and other vacation rental sites have used to argue that they are not responsible for policing the listings on their sites.

The city subpoenaed Airbnb in 2017, seeking data it could use to crack down on unpermitted vacation rental listings. In June, the council adopted a new ordinance that banned Airbnb from collecting fees for unpermitted rentals.

The city and Airbnb signed the new data-sharing deal on August 30.

Thomas Lannom, the director of Portland’s Revenue Bureau called the data-sharing agreement “the toughest in the nation” in an email to the mayor and city council.

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Starting this December, the company has agreed to provide regulators with data on its vacation rental listings on a monthly basis.

Data the city will receive on listings includes the name, mailing address and contact information for the person listing the property, address of the rental location, a description and URL for the listing, and booking and transaction information including the number of guests.

Most of that data will be considered public record, and information about permitted short-term rentals will be publicly available on the city’s Portland Maps website.

Beginning January 1, Airbnb will remove listings posted by hosts who do not give permission to have their data shared with city regulators. Lannom said he expects that could trigger Airbnb to remove up to 1,500 listings in Portland.

In exchange, the city has agreed to streamline its permitting process. It will no longer require in-person inspections for every vacation rental, and it will reduce the number of forms vacation rental owners have to fill out. The city has also agreed to allow Airbnb to continue to list properties that have pending permits, or that appeal a decision to deny them a permit.

The data sharing could lead to a significant crackdown on unpermitted vacation rentals.

Last year, the city auditor estimated that just 22% of listings in the city had permits. Approximately 60% of the listings were for entire homes or apartments.

Portland regulations require hosts to live on the property they are renting for at least nine months each year and to limit guest stays to 30 days. They also have to obtain a permit and a business license.

A second major short-term rental company, Home Away, has reached its own agreement with the city that doesn’t require the company to share its users’ data.

The company has agreed to rely on a registry Portland posts of permitted rentals, and to remove any listings that don’t appear in the registry. The city had reached an initial agreement with Home Away earlier this year.

All other short-term rental platforms have been notified they must also remove their non-compliant listings by September 30.

Editor's note: This story has been updated to reflect that city officials estimate Airbnb could remove up to 1,500 listings if hosts will not agree to share data with regulators.