Tax Filing Deadlines Tax Return Deadlines Partnerships (1065) & S-Corporations (1120S) Forms 1065 and 1120S & extensions are due 3-15 If extended, tax returns are due 9-15 Personal Tax Return (1040), C-corporations (1120), & Gift tax returns (706) Forms 1040, 1120, and 706 & extensions are due 4-15 If extended, tax returns are due 10-15 Non-Profits (990) Forms 990, 990-N, 990-T & extensions are due 5-15 If extended, tax returns are due 11-15 Estates (1041) Tax Returns due 9 months after the date of deathExtensions due 6 months later Quarterly Estimated Income Tax Due Dates 1st quarter 4-15 2nd quarter 6-15 3rd quarter 9-15 4th quarter 1-15 Pay Estimated Taxes @ irs.gov Late Penalties IRS Late Filing Penalties (Failure to File) 5% x federal tax owed / per month Utah Late Filing Penalties 1-5 days late = $20 up to 2% of balance due6-15 days late = $20 up to 5% of balance dueOver 15 days late = $20 up to 10% of balance due IRS Late Payment Penalties (Failure to Pay) 0.5% x federal tax owed / per month Utah Late Payment Penalties 1-5 days late = $20 up to 2% of balance due 6-15 days late = $20 up to 5% of balance due Over 15 days late = $20 up to 10% of balance due IRS Interest Penalty about 0.5% x federal tax owed / per monthUtah Interest Penaltyabout 0.25% x balance due / per month See Also Tax Brackets & Deductions