As governments increasingly publish large public datasets online, officials around the country have faced renewed scrutiny over how transparency tools can also expand privacy and safety concerns. In New York City, Mayor Zohran Mamdani’s administration is under criticism after the Department of Finance published a searchable property roll connected to the city’s new non-primary residence surcharge. The dispute has centered on whether information long available in public records was made materially easier to access when it was compiled into a single searchable database covering nearly 1 million owners and properties.
New York City published the roll as part of its new surcharge process
New York City’s Department of Finance published a supplemental market value roll on July 24, 2026, tied to the city’s new non-primary residence property surcharge, according to the agency’s surcharge guidance and finance notices. The city says the surcharge applies to certain one-, two- and three-family homes valued at more than $5 million, and to condominium and cooperative units valued at $1 million or more, when they are not used as a primary residence.
The city’s online guidance states that the supplemental roll “includes, but is not limited to,” properties that may be subject to the surcharge. It also says the vast majority of properties listed will not owe the tax. According to the Department of Finance FAQ, only roughly 17,000 property owners received letters stating they may be subject to the surcharge.
The scale of the published roll is significantly larger than that notice list. Reporting that cited the underlying file described a database covering nearly 1 million owners, while third-party analyses of the downloadable roll said it spans roughly 1.2 million parcels and about 933,000 owners. The city has not published a single headline total on its public guidance page summarizing the full number of owners included in the roll.
The immediate impact is local because the records cover residential properties across the five boroughs, including co-ops, condos and smaller homes that appear on the supplemental roll whether or not they will ultimately owe the surcharge. The Department of Finance says appearing on the roll does not mean a property is subject to the tax and does not mean the owner received a notice letter.
Critics have focused less on whether the records were technically public and more on how searchable they became after publication in one place. News coverage of the backlash described concerns that names and property addresses were effectively consolidated into a simpler lookup tool, raising objections from opponents who said that format could increase privacy and security risks for some owners.
What is not yet clear is whether City Hall or the Department of Finance conducted and released a separate privacy review before posting the roll in this form. The city’s public guidance explains why the roll exists and who may appeal or seek exemption, but it does not publicly detail any stand-alone risk assessment for publishing owner data in a searchable format.
The broader context is the Mamdani administration’s push to implement New York’s first pied-à -terre tax. In an April 15, 2026 announcement with Gov. Kathy Hochul, the mayor’s office said the measure was intended to raise revenue by taxing certain high-value secondary residences owned by people whose primary homes are outside New York City.
The comptroller’s July economic outlook said the Department of Finance first published proposed rules for the surcharge on June 5 and was expected to finalize them in time for surcharge notices by late August. The same report described the tax as part of the city’s fiscal planning, while the mayor’s office previously said the policy would help close the budget gap and projected it would generate about $500 million annually.
For residents and property owners, the practical effect is that the surcharge process is now moving on a fixed timeline. Department of Finance guidance says owners who received letters may seek exemptions if the property is actually used as a primary residence, and the current application deadline listed by the city is September 18, 2026. The city also states that a determination letter will be sent after documents are reviewed, meaning the published roll remains a preliminary step in a broader tax and appeals process.