Call us at 5184575893 during regular business hours and speak with a representative to request this letter. Town, School and County taxes are payable to the local Tax Receiver in each Town from December 1st to and including May 31st.Exemption applications must be filed with your local assessor's office. See our Municipal Profiles for your local assessor's mailing address. These are the official forms for use in Surrogate's Court proceedings. Welcome to the Town of Islip Receiver of Taxes homepage. This site has been completely revamped to give taxpayers a more user-friendly experience. Letter application on notice to all parties is acceptable for duplicate filing issues that are not resolved prior to placing the matter on the Court calendar. §. Mailing list - Go to the Assessor's Office located on the first floor and request a 200 foot mailing address list and a 500 foot mailing address list. 3.