If you own a condominium, co-op, or townhouse in New York City that appeared on the Department of Finance's pied-à-terre tax database — or if you're not sure whether it did — there are two deadlines arriving faster than most property owners realize. Owners of one- to three-family homes and condominiums must file a primary residence exemption application with the DOF by August 21. Co-op owners have until August 24. These are not the same as the August 30 notification date covered in an earlier post in this series — the notification date is when the DOF sends letters to owners it has identified as potentially subject to the tax. The exemption application deadlines are when owners must respond to assert their primary residence status. For owners who received a notice or whose property appeared on the published database, missing these deadlines means the DOF proceeds with its assessment on the basis that the property is a non-primary residence — which triggers the tax.

At the same time, new data analysis is significantly revising upward what the pied-à-terre tax is actually projected to collect — which suggests the pool of properties that will ultimately be billed is larger than the city's original estimates implied, and that the revenue and political stakes of the rollout are higher than anyone anticipated when the tax was designed.

The Revenue Revision: $1.8 Billion, Not $500 Million

The city projected the pied-à-terre tax would generate approximately $500 million annually from an estimated 11,200 to 31,000 properties. That estimate is now looking significantly conservative. TRD Data analyzed the Department of Finance's newly released dataset and found nearly 19,200 condos and townhouses that could fall under the tax — far more than the city's original estimates. The city could see at least $1.8 billion from the pied-à-terre tax across condos and townhouses. Condos have the potential to generate approximately $1.3 billion in second-home taxes across nearly 12,400 properties with a total value of $27.3 billion. Meanwhile, one- to three-family homes could generate $536 million from the tax across some 6,800 buildings valued at just under $60 billion.

The TRD Data analysis excluded co-ops because it's unclear whether DOF values in the dataset relate to individual units or entire buildings — meaning the $1.8 billion figure likely understates the total potential revenue once co-ops are properly accounted for. The NYC Comptroller had previously estimated the tax could generate $340 million to $380 million after accounting for exemptions and behavioral changes — a range that looked conservative against the $500 million city projection and looks even more conservative against the $1.8 billion TRD Data estimate.

The discrepancy between the various projections reflects a fundamental uncertainty about how many of the properties on the DOF list will ultimately claim and receive primary residence exemptions. If a large share of the 19,200 properties are genuinely occupied as primary residences — which the database controversy of July 28 suggested was likely — the actual revenue will be much lower than $1.8 billion. If many of those properties are genuine pieds-à-terre whose owners have not been paying NYC income tax, the revenue could be substantially higher than the city originally estimated. The exemption application process over the next three weeks will begin to resolve that uncertainty.

The Exemption Process: What You Need to Do Before August 21 or 24

The process for filing a primary residence exemption is straightforward in concept but requires documentation that takes time to assemble. Property owners can apply for an exemption online, which includes uploading documents such as state or federal tax returns or other documents showing the home is their primary residence. The DOF is specifically looking for evidence that the property's address matches the owner's primary residence as indicated on their New York State income tax return — and for supporting evidence of occupancy including utility bills, voter registration records, and records showing consistent use of the property as a primary home.

The documentation requirements differ slightly by property type. For co-op buildings, there is an additional complication: co-op boards are now tasked with collecting the tax from tenant-shareholders. The tax creates new compliance obligations not just for individual owners but for the cooperative corporation itself, which must determine which of its shareholders are subject to the surcharge and ensure collection. Co-op boards that haven't yet addressed this obligation are running out of time.

There is some uncertainty about whether the August deadlines will be extended. Jody Kriss, founder of Kriss Capital, said he anticipates that the city will have to extend the deadline given the number of exemptions likely to be filed. Officials have also said that the city's tax commission will accept appeals until March — the final deadline for homeowners to get themselves off the pied-à-terre tax roll. The March deadline exists as a backstop, but it comes after the initial billing cycle has already begun. Filing now rather than waiting for the March backstop is the approach that avoids being billed while a dispute is pending.

Who Is Actually Likely to Owe the Tax After Exemptions Are Filed

The confusion created by the DOF's database publication — which included nearly one million properties when only 31,000 were supposed to be targeted — has obscured a more specific question: who among the properties on the list is genuinely subject to the tax after applying all available exemptions?

The preliminary roster released July 24 includes around 31,000 homes, most of which are condos and co-ops classified as Class 2 properties. But many won't be subject to the tax, upon closer inspection, because they aren't worth enough or are eligible for other exemptions, said Adrian Diaz, a senior attorney at Hogan Lovells. Mayor Mamdani has said that only property owners who receive a letter from city officials will be impacted — but the broad database publication has created anxiety well beyond that population, and many owners who received no letter are uncertain whether they need to act.

The practical guidance is clear: if your property appeared on the DOF database or if you received a letter, file the exemption application before the August 21 or 24 deadline. If your property did not appear on the database and you did not receive a letter, you are not required to file — but monitoring for any communications from the DOF between now and August 30 is prudent. The August 30 notification date is when the DOF has said it will send formal determination letters to owners it believes are subject to the tax — which is distinct from the preliminary database and from the letters that have already gone out to some owners.

For owners in genuine gray areas — those who split time between New York and another state, who own the property but have a family member in residence, or whose primary residence status may be ambiguous — the advice from real estate attorneys has been consistent: document your primary residence status thoroughly and file the exemption application now rather than waiting to see if the DOF reaches a different conclusion on its own. The penalty for providing inaccurate documentation is up to 50% of the tax owed, and the audit authority extends six years. The cost of getting this right before the deadline is far lower than the cost of resolving it afterward.

The August 30 Date and What Comes After

The full pied-à-terre tax timeline now has several overlapping deadlines that are worth tracking in sequence. August 21: condo and townhouse owners must file primary residence exemption applications. August 24: co-op owners must file. August 30: the DOF sends formal determination letters to owners it has identified as subject to the tax. After August 30: owners who receive determination letters have the opportunity to contest them — a separate process from the pre-deadline exemption application. March 2027: the tax commission's final deadline for appeals.

At Dover Property Group, we have been tracking the pied-à-terre tax rollout since it took effect July 1 and are monitoring the exemption deadline and the August 30 notification process closely. If you have questions about whether your property may be subject to the tax, what documentation the exemption application requires, or how to navigate the contest process if you receive a determination letter, our team is glad to help connect you with the right resources before the deadlines arrive.

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Sources: The Real Deal / TRD Data — NYC Pied-à-Terre Tax: Properties That Could Be Affected, August 2026 · The Real Deal — NYC's First Pied-à-Terre Tax Collection Tangles Primary Homeowners · TaxProf Blog — Even More on NYC's Pied-à-Terre Tax, August 3, 2026 · Cole Schotz — The New Price of Luxury: What NYC's Pied-à-Terre Tax Means to Part-Time Residents · The Real Deal / TRD Data — The Data Drop: A Look at the Universe of NYC Pieds-à-Terre · NYC Comptroller — The Pied-à-Terre Tax and Its Potential Revenues · PiedATerreTax.nyc — Every Building on the DOF Roll, Searchable

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About the Author
Dover Property Group is a New York City property management firm working with building owners and tenants across all five boroughs. Our team tracks market conditions, compliance requirements, and neighborhood-level trends to help owners protect their assets and tenants navigate one of the most complex rental markets in the country.