No information is available for this page. Exemption applications must be filed with your local assessor's office.See our Municipal Profiles for your local assessor's mailing address. You must file exemption applications with your local assessor's office. See Municipal Profiles for your local assessor's mailing address. The deadline for filing an exemption with the Nassau County Department of Assessment is January 2nd. To receive an application, write to the Nassau County Department of Assessment at 240 Old Country Road, Mineola, NY 11501, or call (516) 571-1500. Nassau County Florida Tax Collector Office Homestead Exemption - NassauTaxes. File Online for Homestead Exemption Reduction. AR3 – is used if you disagree with the property's tax class or exemptions.