October 15
- Extended deadline for C corporation and individual returns
October 30
- Quarterly estimated tax payments

October 15
October 30
Deadline for employees who received $20 or more in tips during August to report them to their employers using Form 4070.
September 15, 2026
Q3 Estimated Tax Payment Due: Third-quarter estimated tax payments for 2026 (Form 1040-ES) are due for self-employed individuals and gig workers.
Extended Partnership & S-Corp Returns: Final deadline to file extended income tax returns for calendar-year partnerships (Form 1065) and S-corporations (Form 1120-S).
Employer Payroll Deposits: Deposit Social Security, Medicare, and withheld income taxes for August if the monthly deposit rule applies.
September 30, 2026
Extended due date for Form 1041 (Income Tax Return for Estates and Trusts).
April 15
March 16 (March 15 is Sunday)
March 31
February 2
February 28 (Saturday → Due Monday, March 2, 2026)
January 15
January 31 (Saturday → Due Monday, February 2, 2026)
Individuals: Reporting November tip income, $20 or more, to employers (Form 4070).
Corporations: Paying the fourth installment of 2025 estimated income taxes.
Partnerships: Paying the fourth installment of 2025 estimated income taxes.
Tax Exempt Orgs: Deposit Estimated Tax for 4th quarter due on Unrelated Business Taxable Income for Tax-Exempt Organizations. Use Form 990-W to determine the amount of estimated tax payments required.
Employers: Establishing a retirement plan for 2025 (generally other than a SIMPLE, a Safe-Harbor 401(k) or a SEP)