Does this include state deadlines?

No. It covers federal dates only. Most states follow the federal individual date, but entity and payroll dates vary.

Where do disaster postponements fit?

The IRS announces disaster relief by area. Check the IRS disaster relief page for any client in an affected county before relying on these dates.

Calendar · Publication 509 (2026)

2026 tax calendar for CPA firms

One table of the federal dates that drive a firm’s year, with weekend and holiday shifts already applied. Copy it into your own calendar or print it for the team wall.

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2026
Date	What is due
Thursday, January 15, 2026	Individuals: final installment of 2025 estimated tax
Monday, February 2, 2026	Form W-2 copies to employees for 2025 Form W-3 with Copy A of all Forms W-2 Form 1099-NEC to the IRS for nonemployee compensation paid in 2025 Annual information statements to recipients of certain 2025 payments Form 941 for the fourth quarter of 2025 and Form 940 for 2025
Tuesday, February 10, 2026	Form 940 for 2025 if all tax was deposited on time and in full
Tuesday, February 17, 2026	Forms 1099-B and 1099-S statements due to recipients
Monday, March 2, 2026	Paper information returns (for example, certain Forms 1099) to the IRS Paper Forms 1094-C / 1095-C and 1094-B / 1095-B to the IRS
Monday, March 16, 2026	Form 1065 for calendar year 2025, with Schedules K-1 Form 1120-S for calendar year 2025, with Schedules K-1 Form 7004 to request an automatic 6-month extension for either
Tuesday, March 31, 2026	Electronic filing of Forms 1097, 1098, 1099 (except 1099-NEC), 3921, 3922 and W-2G
Wednesday, April 15, 2026	Form 1040 or 1040-SR for 2025, and any tax due Form 4868 for an automatic 6-month extension Form 1120 for calendar year 2025 (Form 7004 to extend) First installment of 2026 estimated tax for individuals and corporations
Thursday, April 30, 2026	Form 941 for the first quarter of 2026
Monday, May 11, 2026	Form 941 for the first quarter if all tax was deposited on time and in full
Monday, June 15, 2026	Second installment of 2026 estimated tax for individuals and corporations
Friday, July 31, 2026	Form 941 for the second quarter of 2026 Form 5500 or 5500-EZ for calendar year 2025 plans
Monday, August 10, 2026	Form 941 for the second quarter if all tax was deposited on time and in full
Tuesday, September 15, 2026	Extended Form 1065 and Form 1120-S for 2025 Third installment of 2026 estimated tax for individuals and corporations
Thursday, October 15, 2026	Extended Form 1040 / 1040-SR for 2025 Extended Form 1120 for calendar year 2025
Monday, November 2, 2026	Form 941 for the third quarter of 2026
Tuesday, November 10, 2026	Form 941 for the third quarter if all tax was deposited on time and in full
Tuesday, December 15, 2026	Corporations: fourth installment of 2026 estimated tax

Calendar-year filers. From IRS Publication 509 (2026), Tax Calendars. Checked October 21, 2026.

How to use it in the firm

Work back from each date. Partnership and S corporation returns in March need books closed by the client in January, which means the document chase starts before the holidays.

The dates are for calendar-year filers. Fiscal-year entities follow the same month-based rules counted from their own year end.

Set internal cutoffs two to three weeks before each filing date.
Assign an owner to each date, not just to each client.
Book extension decisions as their own deadline, a week before the filing date.

Dates that moved because of weekends

Several 2026 dates fall later than the rule suggests. W-2s and 1099-NEC forms were due February 2 because January 31 was a Saturday, and partnership and S corporation returns were due March 16 because March 15 was a Sunday.

FAQ

Frequently asked questions

Does this include state deadlines?: No. It covers federal dates only. Most states follow the federal individual date, but entity and payroll dates vary.
Where do disaster postponements fit?: The IRS announces disaster relief by area. Check the IRS disaster relief page for any client in an affected county before relying on these dates.