2026 reference
2026 Small Business Tax Calendar
All major 2026 tax deadlines for sole proprietors, freelancers, LLCs, S-Corps, partnerships, and C-Corporations — in chronological order.
All 2026 tax deadlines
Final quarterly payment for 2025 income (September–December). Sole proprietors, freelancers, S-Corp shareholders, and partners. Form 1040-ES.
Employers must furnish W-2s to employees AND file with SSA. Businesses must furnish 1099-NEC to contractors AND file with IRS. Both paper and electronic — same deadline.
Paper 1099-MISC forms (other than NEC) due to IRS. Electronic filing deadline is March 31, 2026.
Form 1120-S (S-Corp) and Form 1065 (Partnership) due. Filing extension: September 15, 2026. The 15th falls on a Sunday, so deadline shifts to Monday March 16 — but check IRS.gov for confirmation.
Electronic 1099-MISC forms (boxes other than NEC) due to IRS. Also: electronic filing of W-2s via SSA Business Services Online if not filed by Jan 31.
Form 1040 (individual) and C-Corporation (Form 1120) due. Q1 2026 estimated tax payment (January–March income). Extension to October 15 available for 1040 (file Form 4868). IRA contribution deadline for 2025 tax year.
Second quarterly payment for April–May income. Note: Q2 covers only 2 months (April–May), not 3. Form 1040-ES.
Q3 2026 estimated tax payment (June–August income). Extended Form 1120-S and Form 1065 returns also due today. Form 1040-ES.
Final deadline for Form 1040 with extension (Form 4868). Extended C-Corporation Form 1120 also due. No further extensions available.
Final 2026 quarterly payment (September–December income). Alternative: file your 2026 Form 1040 and pay any balance due by January 31, 2027 to skip this payment.
Penalties for missing deadlines
| What you miss | Penalty | How to avoid |
|---|---|---|
| Quarterly estimated tax | ~7–8% annualized on underpaid amount | Pay safe harbor amount (90% of current year or 100% of prior year tax) |
| 1099-NEC filing | $60–$310 per form depending on days late; up to $630 per form for intentional disregard | File by January 31 — no extensions available for 1099-NEC |
| Individual return (no extension) | 5% of unpaid tax per month (up to 25%) + interest | File Form 4868 by April 15 for automatic 6-month extension. Extension of time to file ≠ extension of time to pay. |
| Payroll tax deposit | 2–15% of deposit depending on days late | Deposit on time via EFTPS. Monthly vs semi-weekly rules depend on lookback period. |
Frequently asked questions
When are 2026 quarterly estimated taxes due?+
Q1 (January–March income): April 15, 2026. Q2 (April–May income): June 15, 2026. Q3 (June–August income): September 15, 2026. Q4 (September–December income): January 15, 2027. If any date falls on a weekend or federal holiday, the deadline shifts to the next business day.
What is the penalty for missing a quarterly tax deadline?+
The IRS charges an underpayment penalty based on the federal short-term rate plus 3% (typically 7–8% annualized in 2026), applied to the underpaid amount for each day it's late. The penalty is calculated quarterly, so missing Q1 accumulates more penalty than missing Q4. You avoid the penalty by paying at least 90% of your current-year tax or 100% of last year's tax (110% if AGI exceeded $150,000).
When are W-2 and 1099-NEC forms due in 2026?+
Both W-2 and 1099-NEC are due to recipients AND to the IRS/SSA by January 31, 2026 (for 2025 tax year payments). This is the same deadline for both paper and electronic filing — there is no extension for 1099-NEC. Filing late carries penalties of $60–$310 per form depending on how late.
When is the corporate tax return due for 2026?+
C-Corporation (Form 1120): April 15, 2026, or the 15th day of the 4th month after fiscal year end. Extension to October 15, 2026 available. S-Corporation (Form 1120-S): March 17, 2026 (15th day of 3rd month after year end). Extension to September 15, 2026 available. Partnership (Form 1065): March 17, 2026. Extension to September 15, 2026 available.
What is safe harbor for estimated taxes?+
Safe harbor means you pay enough estimated tax to avoid IRS underpayment penalties — even if you end up owing more at filing. You qualify if you pay: (a) 90% of your current year's total tax, OR (b) 100% of last year's total tax liability (110% if last year's AGI exceeded $150,000). Paying the safe harbor amount via equal quarterly installments protects you from penalties regardless of income fluctuations.
Do freelancers and self-employed people pay quarterly taxes?+
Yes. If you expect to owe $1,000 or more in federal income tax for 2026, you must make quarterly estimated payments. Self-employment tax (15.3% on net earnings) and federal income tax are both included in quarterly payments. Most states with income tax also require quarterly estimated payments with their own deadlines (often the same as federal or within a few days).