2023 individual quarterly estimated Federal tax payments are due September 15, 2023 and January 15, 2024 for the remainder of the tax year. The extended business tax deadline is September 15, 2023 and the extended individual tax deadline is October 16, 2023. In order to meet these deadlines, UMMC must receive all information to prepare your returns by the dates identified below. If we do not receive all information needed by these dates, we cannot guarantee timely filings. Documentation must be provided as follows: Nonprofits (with calendar year-end) – extensions are valid until November 16, 2023 and information will be needed by October 16, 2023. S Corporations and Partnerships (with calendar year-end) – information will be needed by August 18, 2023. Individuals and C Corporations (with calendar year-end) – information will be needed by September 15, 2023.