Every key federal tax deadline for small businesses in 2026 and early 2027, adjusted for weekends.
| Date | What’s due | Who it applies to |
|---|---|---|
| Jan 15, 2026 | Estimated tax — 4th payment for 2025 (Form 1040-ES) | Self-employed, freelancers, owners of pass-through businesses |
| Feb 2, 2026 | Forms W-2 and 1099-NEC due to recipients and the IRS/SSA (Jan 31 falls on a Saturday) | Employers and businesses paying contractors |
| Mar 16, 2026 | S corporation (Form 1120-S) and partnership (Form 1065) returns, or extension (Mar 15 falls on a Sunday) | S corps, partnerships, multi-member LLCs |
| Apr 15, 2026 | Individual returns (Form 1040) and C corporation returns (Form 1120), or extension; estimated tax — 1st payment for 2026 | Individuals, sole props, single-member LLCs, C corps |
| Jun 15, 2026 | Estimated tax — 2nd payment for 2026 | Self-employed, pass-through owners |
| Sep 15, 2026 | Estimated tax — 3rd payment for 2026; extended 1120-S and 1065 returns | Self-employed, S corps, partnerships |
| Oct 15, 2026 | Extended individual (1040) and C corporation (1120) returns | Anyone who filed an extension |
| Jan 15, 2027 | Estimated tax — 4th payment for 2026 | Self-employed, pass-through owners |
| Feb 1, 2027 | Forms W-2 and 1099-NEC for 2026 (Jan 31 falls on a Sunday) | Employers and businesses paying contractors |
| Mar 15, 2027 | 1120-S and 1065 returns for 2026, or extension | S corps, partnerships |
| Apr 15, 2027 | 1040 and 1120 returns for 2026, or extension; 1st estimated payment for 2027 | Individuals and C corps |
Federal deadlines for calendar-year filers. Fiscal-year businesses, disaster-area postponements and state deadlines can differ — check IRS.gov and your state’s department of revenue, or ask your CPA.
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