For the 2026 tax year, the IRS has adjusted several standard deadlines because they fall on weekends or holidays. Below are the critical due dates to ensure timely filing and payment.

Key Dates for Individuals

• January 15, 2026: Deadline to pay the final installment of 2025 estimated taxes (Q4).

• April 15, 2026: Tax Day. Annual income tax returns (Form 1040) and Q1 2026 estimated tax payments are due. Last day to file Form 4868 for an automatic 6-month extension.

• June 16, 2026: Q2 2026 estimated tax payments are due (moved from June 15, which is a Sunday).

• September 15, 2026: Q3 2026 estimated tax payments are due.

• October 15, 2026: Final deadline to file 2025 income tax returns for those who requested an extension.

Key Dates for Businesses

• February 2, 2026: Deadline to file Forms W-2 and 1099-NEC/MISC (moved from Jan. 31, which is a Saturday).

• March 16, 2026: Tax returns due for Partnerships (Form 1065) and S-Corporations (Form 1120-S) (moved from March 15, which is a Sunday).

• April 15, 2026: Tax returns due for C-Corporations (Form 1120) and Estates/Trusts (Form 1041).

• September 15, 2026: Extended filing deadline for Partnerships and S-Corporations.

• October 15, 2026: Extended filing deadline for C-Corporations.

• December 15, 2026: Q4 estimated tax payments due for C-Corporations (Form 1120-W).

Please reference our full 2026 Tax Calendar, complete with forms, here.