Mayor Zohran Mamdani and Department of Finance (DOF) Commissioner Richard Lee on Saturday announced the deadline extension, which gives eligible property owners until September 18 to submit exemption applications for surcharges on their non-primary residences. Additionally, there have been several instances of individuals with only one primary NYC residence being notified that they may be subject to the tax. Only property owners who have received notices are subject to the surcharge. “There has been both a willful and an unintentional conflation of both the property tax roll and these letters,” he said. The city will also reach out directly to homeowners who received notices, where contact information is available, to answer questions and provide guidance on the exemption and appeals process.