Filing Deadlines
Every federal date for any entity type and year end
Pick an entity type and year end. Get every federal deadline for the cycle: the return, its extension, estimated payments, payroll deposits and information returns, with weekend and holiday shifts already applied.
Where these dates come from
Every date below is worked out from the Internal Revenue Code and the Treasury regulations, read against the text of each section listed here. The links go to the official public copies.
| What it sets | The rule | Where it is written |
|---|---|---|
| Individual returns (1040), estates and trusts (1041) | 15th day of the 4th month after the year ends | 26 U.S.C. 6072 (a) · 26 CFR 1.6072-1 |
| Partnership returns (1065) | 15th day of the 3rd month | 26 U.S.C. 6072 (b) |
| S corporation and C corporation returns (1120-S, 1120) | 15th day of the 3rd month (S) or 4th month (C); a C corporation year ending June 30 that began before 2026: the 3rd month | 26 CFR 1.6072-2 |
| Nonprofit returns (990) | 15th day of the 5th month | 26 CFR 1.6033-2(e) |
| Extensions | 6 months; estates and trusts 5 and a half months; a June 30 C corporation that began before 2026, 7 months | 26 CFR 1.6081-4 · 26 CFR 1.6081-2 · 26 CFR 1.6081-3 · 26 CFR 1.6081-6 · 26 CFR 1.6081-9 |
| Estimated tax (1040-ES, 1041-ES, 1120-W) | Four installments; a fiscal year uses the months that correspond | 26 U.S.C. 6654 (c), (k) · 26 U.S.C. 6655 (c) |
| Payroll (941, 940) and W-2 | 941: last day of the month after the quarter; 940 and W-2: January 31 | 26 CFR 31.6071(a)-1 · 26 CFR 31.6051-1 |
| 1099-NEC and 1099-MISC | NEC: January 31; MISC: February 28 on paper, March 31 electronically | 26 CFR 1.6041-6 |
| Weekends and holidays | A date on a Saturday, Sunday or legal holiday moves to the next business day | 26 U.S.C. 7503 · 26 CFR 301.7503-1 |
Due dates, extension periods, estimated tax installments, payroll and information return dates, and the weekend and holiday rule read against 26 U.S.C. 6071, 6072, 6654, 6655 and 7503 and the regulations under them.
| Date | Form | Requirement |
|---|
How these dates are calculated
Partnership and S corporation returns are due the fifteenth day of the third month after the year end. C corporation and individual returns fall on the fifteenth day of the fourth month, except a C corporation whose year ends June 30 and began before 2026, which files in the third month and gets seven months of extension. Estates and trusts follow the fourth month; exempt organizations the fifth. Extensions add six months for most entities, five and a half for estates and trusts. Estimated payments follow the tax year, so a fiscal year moves them.
When a due date lands on a Saturday, Sunday, or a legal holiday in the District of Columbia, it rolls to the next business day. That includes Emancipation Day on April 16, which is why the April filing date sometimes moves. This tool applies that shift and marks any date it moved, so you can see which deadlines are not on their nominal day this year.
What is not included
State income and franchise filings, sales and use tax, local business taxes, and industry-specific returns vary too much to generate reliably. Situation-driven deadlines, such as installment agreement dates, collection due process windows, and amended return statutes, are not here either. Treat this as the recurring federal skeleton, not a complete compliance calendar.
Who built this
Claremont Security handles managed compliance and AI governance for accounting and tax practices. If you are thinking about how client data moves through Copilot or any other AI assistant in your firm, we should talk. See also the IRS Notice Decoder, and more free tools at claremontsecurity.com/tools.