Tax Filing Deadlines 2020 Tax Deadlines Partnerships & S-Corporations Tax Returns due March 16th, 2020Extensions due September 15th, 2020 Sole-Proprietors, Individuals, C-corporations, & Gift tax returns Tax Returns due April 15th, 2020Extensions due October 15th, 2020 Non-Profits Tax Returns due May 15th, 2020Extensions due November 16th, 2020 Estates Tax Returns due 9 months after the date of deathExtensions due 6 months later 2019 Estimated Tax Due Dates 1st quarter April 15th, 20192nd quarter June 17th, 20193rd quarter Sept 16th, 20194th quarter Jan 15th, 2020 Pay Estimated Taxes @ irs.gov See Also: Tax Brackets & Deductions