- Jan. 15, 2026 – Fourth quarter estimated tax payments due for 2025.
- Jan. 31, 2026:
- Deadline to send Form W-2 to your employees.
- Deadline to send certain 1099 forms such as Form 1099-NEC or Form 1099-K.
- March 16, 2026:
- Taxes due for partnerships, S corporations, or multi-member LLCs taxed as partnerships. This is the due date for calendar year business filers. If your business uses a fiscal year instead, your tax due date is the 15th day of the third month after the close of your tax year. For example, if your business’s fiscal year is June 1 to May 31, your business tax return due date would be Aug. 15 — three months and 15 days after May 31.
- Deadline to request a tax extension for partnerships, S corps, and LLCs taxed as partnerships.
- Deadline to file Form 2553 to switch your business election to an S corp for tax year 2026.
- April 15, 2026:
- Taxes due for C corporations, sole proprietors, single-member LLCs, and LLCs taxed as corporations. If your business uses a fiscal tax year, you must file your business tax return by the 15th day of the third month after the end of your tax year.
- Deadline to request a tax extension for C corps, sole proprietors, single-member LLCs, and LLCs taxed as corporations.
- May 15, 2026 – Tax returns due for tax-exempt nonprofits that follow a calendar year tax period.
- June 15, 2026 – Second quarter estimated tax payments due for 2026.
- Sept. 15, 2026:
- Third quarter estimated tax payments due for 2026.
- Extended tax deadline for partnerships and S corps that filed a tax extension.
- Oct. 15, 2026 – Extended tax deadline for C corps, sole proprietors, and certain LLCs that filed a tax extension.
- Nov. 16, 2026 – Extended tax deadline for tax-exempt nonprofits that follow a calendar year tax period.
- Jan. 15, 2027 – Fourth quarter estimated tax payments due for 2026.
If you’d like a complete picture of all the 2026 tax calendar due dates, check out IRS Publication 509