Quick answer: In 2026, partnership and S corporation returns were due March 16, and sole proprietor, single-member LLC, and C corporation returns were due April 15. Extended deadlines are September 15 (partnerships, S corps) and October 15 (individuals, C corps).
Whether you’re a one-person show or managing a growing team, your filing deadlines depend on how your business is set up. Here are the key 2026 federal dates for calendar-year businesses.
👤 Sole proprietors and single-member LLCs
You report business income on Schedule C with your personal Form 1040.
- April 15, 2026: Form 1040 with Schedule C and Schedule SE due
- October 15, 2026: Extended deadline if you filed Form 4868
- Estimated taxes: April 15, June 15, September 15, 2026, and January 15, 2027
An extension gives you more time to file, not more time to pay.
Never miss a 2026 tax deadlineFree calendar with every date, plus reminders in Google Calendar.
Get it free🤝 Partnerships and multi-member LLCs
- March 16, 2026: Form 1065 due and Schedule K-1s to partners (March 15 fell on a Sunday)
- September 15, 2026: Extended deadline with Form 7004
🏢 S corporations
- March 16, 2026: Form 1120-S due, with K-1s to shareholders
- September 15, 2026: Extended deadline with Form 7004
S corp owners who work in the business must run payroll and pay themselves a reasonable salary, so the payroll dates below apply too.
🏦 C corporations
- April 15, 2026: Form 1120 due
- October 15, 2026: Extended deadline with Form 7004
- Estimated taxes: April 15, June 15, September 15, and December 15, 2026
👥 Payroll and contractor deadlines
- Form 941 (quarterly payroll): April 30, July 31, November 2, 2026 (October 31 is a Saturday), and February 1, 2027
- W-2s, 1099-NECs, and Form 940 for 2026: February 1, 2027 (January 31 is a Sunday)
New for 2026: The 1099-NEC and 1099-MISC reporting threshold rises from $600 to $2,000 for payments made in 2026. Payment apps and marketplaces send a 1099-K only when you pass $20,000 and 200 transactions. All of your income is still taxable whether or not you receive a form.
🗺 Don’t forget your state
Most states have their own income, franchise, or sales tax deadlines that don’t always match federal dates. Add them from your state revenue department’s website.
✅ Quick checklist
- Confirm your business type and which forms you file
- Add every date above to your calendar with a one-week reminder
- Decide early whether you’ll need an extension
- Keep your books current so filing is a summary, not a scramble
Keep the dates handy with the free 2026 tax deadlines calendar, and see Estimated Tax Deadlines 2026 for quarterly payment rules.
Frequently asked questions
March 16, 2026 for calendar-year businesses, because March 15 fell on a Sunday. The extended deadline is September 15, 2026.
A single-member LLC taxed as a sole proprietorship files Schedule C with Form 1040, due April 15, 2026, or October 15, 2026 with an extension.
For payments made in 2026, you generally file a 1099-NEC for contractors paid $2,000 or more, up from $600. Those forms are due February 1, 2027.
No. An extension only extends the filing deadline. Taxes owed are still due by the original deadline to avoid penalties and interest.
This article is for educational purposes only and isn’t tax or legal advice. Figures reflect IRS guidance for 2026; check with a qualified tax professional about your situation.
