The Mamdani administration has extended the deadline for New Yorkers to apply for an exemption from the pied-à-terre tax to October 6, while admitting to mistakenly notifying over 1,000 property owners that they might owe the tax. This marks the second extension for the deadline, which was initially set for late August and then moved to September 18 following public backlash.

The Department of Finance (DOF) sent out 17,000 notices as part of the luxury second home tax's rollout, warning recipients they could face the tax unless they appealed. However, the city acknowledged in recent court filings that at least 1,210 of these notices were sent in error to primary residences. The DOF is working to rectify these errors as more 2025 personal income tax data becomes available.

As of Tuesday, approximately 5,500 notice recipients had submitted appeals, with 2,900 granted, and 11,000 individuals had begun exemption applications. The court documents were filed in connection with an ongoing lawsuit challenging the rollout of the surcharge.

The pied-à-terre tax, established by state law and approved by Governor Kathy Hochul earlier this spring, applies to one- to three-family homes valued at $5 million or more and co-ops and condos valued at $1 million or more that are unoccupied and not primary residences. The law went into effect last month.

Randy Mastro, an attorney representing the plaintiffs in the Staten Island Supreme Court suit, described the city's filing as an admission of a significant error. He argued that the administration shifted the burden onto homeowners to prove they live in their own homes, rather than conducting thorough initial assessments.

The city also noted in its filings that the five homeowners who initially filed the lawsuit have had their exemptions approved. Additionally, the DOF is preparing to send out another 10,800 letters by August 31 to property owners who need to prove their primary residence status. These include 6,400 letters for entity- and trust-owned properties and 4,400 for addresses where primary residence status could not be determined.

A spokesperson for the DOF stated that the administration is committed to providing New Yorkers with the necessary time and information. The receipt of 2025 tax data from the state prompted the decision to extend the exemption application deadline further.

The next court hearing for oral arguments in the case is scheduled for August 31.