Introduction
Small business tax deadlines don't start and end with April 15 — depending on your entity type, whether you have employees, and whether you pay estimated taxes, you may have obligations spread across the entire year. This guide pulls every major 2026 federal deadline into one reference so nothing catches you by surprise.
Note: This covers federal deadlines. State tax deadlines often differ and are set independently — confirm your specific state's dates with your state's department of revenue. Always verify current deadlines on IRS.gov as this guide's publication date, since deadlines occasionally shift.
Table of Contents
- The Full 2026 Deadline List
- Quarterly Estimated Tax Payments
- Entity Filing Deadlines
- Payroll and Contractor Deadlines
- Extensions: What They Do and Don't Do
- A Simple Way to Never Miss One
- FAQ
- Conclusion
The Full 2026 Deadline List
| Date | Deadline |
|---|---|
| January 15, 2026 | Q4 2025 estimated tax payment due |
| January 31, 2026 (shifts to Feb 2, 2026 — Saturday) | 1099s and W-2s due to recipients; Form 940 (FUTA) annual return due |
| March 16, 2026 (shifted from Mar 15 — Sunday) | Partnership and S-corp returns due (Form 1065, 1120-S), K-1s issued |
| April 15, 2026 | Individual/sole proprietor/C-corp returns due (Form 1040, 1120); Q1 2026 estimated tax due |
| April 30, 2026 | Form 941 (Q1 payroll tax return) due |
| June 15, 2026 | Q2 2026 estimated tax payment due |
| July 31, 2026 | Form 941 (Q2 payroll tax return) due |
| September 15, 2026 | Q3 2026 estimated tax due; extended partnership/S-corp returns due |
| October 15, 2026 | Extended individual/C-corp returns due |
| October 31, 2026 | Form 941 (Q3 payroll tax return) due |
| January 15, 2027 | Q4 2026 estimated tax payment due |
| January 31, 2027 | Form 941 (Q4 payroll tax return) due; Form 940 annual return due |
Quarterly Estimated Tax Payments
If you're self-employed, a freelancer, or a business owner who expects to owe $1,000 or more in tax for the year, you're generally required to pay estimated taxes quarterly rather than in one lump sum at filing time:
- Q1 2026: April 15, 2026
- Q2 2026: June 15, 2026
- Q3 2026: September 15, 2026
- Q4 2026: January 15, 2027
Note that these "quarters" aren't evenly spaced calendar quarters — Q2's window is only 2 months, and Q4's is 4 months, which catches people off guard the first year they're paying estimated taxes.
Entity Filing Deadlines
Your business's legal structure determines your filing deadline:
- Partnerships and S-corporations (Form 1065, 1120-S): March 16, 2026 (shifted from March 15, which falls on a Sunday). K-1s must go out to owners by this date too.
- Sole proprietors, single-member LLCs, and C-corporations (Schedule C with Form 1040, or Form 1120): April 15, 2026 — the same date as individual tax returns.
- Extended deadlines: Partnerships/S-corps extend to September 15, 2026; individuals/C-corps extend to October 15, 2026.
Payroll and Contractor Deadlines
If you have employees or pay contractors:
- January 31, 2026 (shifting to February 2, 2026 since Jan 31 is a Saturday): Issue W-2s to employees and 1099s to contractors
- Form 941 (quarterly payroll tax return): due the last day of the month following each quarter — April 30, July 31, October 31, 2026, and January 31, 2027 for Q4
- Form 940 (annual FUTA return): due January 31 each year for the prior year
Remember: these are filing deadlines for the returns. Your actual payroll tax deposit schedule (monthly or semi-weekly, assigned by the IRS) is separate and more frequent — see our US payroll processing guide for details on deposit timing.
Extensions: What They Do and Don't Do
A 6-month extension is available for both business returns (Form 7004) and individual/sole proprietor returns (Form 4868). This is genuinely useful if you need more time to prepare an accurate return — but there's a critical catch: an extension gives you more time to file, not more time to pay. Any tax you owe is still due by the original deadline. Filing an extension without paying an estimated amount owed by the original deadline still results in penalties and interest on the unpaid balance, even though your paperwork isn't technically late.
A Simple Way to Never Miss One
- Set calendar reminders 2 weeks before each deadline above, not on the day itself — this gives you a buffer to gather documents or address a problem
- If you use payroll software (Gusto, QuickBooks Payroll, ADP), most handle Form 941/940 filing automatically — confirm this is actually turned on for your account rather than assuming
- Keep your bookkeeping current throughout the year rather than scrambling before each deadline — accurate, up-to-date books make every one of these deadlines faster to hit
- If any date above falls on a weekend or federal holiday, the practical deadline shifts to the next business day — but don't count on this without double-checking your specific date
Conclusion
Small business tax deadlines are spread across the entire calendar year, not concentrated in April — quarterly estimated payments, entity-specific filing dates, and payroll/contractor reporting deadlines all have their own timing. Bookmark this page or set your own reminders now, well before each date arrives, rather than discovering a deadline the week it's due.
If you'd like help staying ahead of these deadlines with organized, up-to-date books year-round, get in touch for a free consultation.