2026 – Upcoming Income Tax Deadlines: Key Dates to Know

Staying ahead of tax deadlines is essential for individuals and businesses alike, especially in regulated industries like cannabis where compliance matters year-round. As the 2026 tax season approaches, understanding key federal filing and payment dates can help you avoid penalties, interest, and last-minute stress.

Below is a breakdown of the most important income tax deadlines to keep on your radar.

Tax Deadlines

1. Individual Tax Filings: April 15, 2026

For most individual taxpayers, the deadline to file your 2025 federal income tax return is Wednesday, April 15, 2026.

If you’re unable to file by this date, you may request an automatic extension, which grants you until October 15, 2026 to file. Keep in mind that an extension to file does not extend the time to pay. Any taxes owed are still due by April 15 to avoid penalties and interest.

2. S Corporation and Partnership Filings: March 16, 2026

S corporations and partnerships must file their 2025 tax returns by Monday, March 16, 2026, since March 15 falls on a Sunday.

These entities file IRS Form 1120-S or Form 1065, respectively. Extensions are available and move the filing deadline to September 15, 2026, but taxes owed must still be paid by the original due date.

3. C Corporation Tax Filings: April 15, 2026

C corporations operating on a calendar-year basis must file their 2025 IRS Form 1120 by April 15, 2026.

Corporations may request a six-month extension to file, moving the deadline to October 15, 2026, though any taxes due must still be paid by April 15.

4. LLC Tax Filings: It depends

The IRS does not actually recognize "LLC" as a tax category. Instead, they treat you as a C-corporation, an S-corporation, a partnership, or as part of the owner's personal tax return (disregarded entity).

• LLC’s electing to be treated as a partnership or S-Corporation must file by March 16, 2026.
• LLC’s electing C-corporation status or which are being included as part of the owner’s personal return must file by April 15, 2026.

Estimated Tax Payments

5. Quarterly Estimated Tax Payments: Individuals

Individuals who are self-employed or who do not have sufficient withholding must generally make quarterly estimated tax payments. The key dates for 2026 are:

• January 15, 2026 – 4th quarter estimated payment for 2025
• April 15, 2026 – 1st quarter estimated payment for 2026
• June 15, 2026 – 2nd quarter estimated payment for 2026
• September 15, 2026 – 3rd quarter estimated payment for 2026

6. Quarterly Estimated Tax Payments: C Corporations

C corporations also make estimated tax payments throughout the year, generally due on the following dates:

• April 15, 2026 – 1st quarter estimated payment for 2026
• June 15, 2026 – 2nd quarter estimated payment for 2026
• September 15, 2026 – 3rd quarter estimated payment for 2026
• December 15, 2026 – 4th quarter estimated payment for 2026

Estimated Tax Calculations

Estimated tax payments are prepayments of income tax made throughout the year to avoid underpayment penalties. While calculations differ between individuals and corporations, the general approach includes estimating total income, applying deductions and credits, and following IRS safe harbor rules.

For individuals, safe harbor rules typically require paying at least 90% of the current year’s tax liability or 100% of the prior year’s liability (110% for higher-income taxpayers).For corporations, the general rule is paying 100% of the current year’s tax or the prior year’s tax liability.

Additional Tips

• Adjust During the Year: If your income changes, recalculate estimated payments to avoid over- or underpayment.
• State Deadlines: Many states have their own estimated payment requirements and deadlines.
• Penalties: The IRS assesses penalties for underpayment, making proactive planning essential.

Stay Ahead of the Tax Deadlines

While these dates cover the most common federal deadlines, additional filing or payment requirements may apply depending on your specific situation, including state obligations or amended returns.

At VERDANT Strategies, we help clients stay compliant, plan ahead, and make informed financial decisions. If you have questions about upcoming deadlines or want support preparing for the 2026 tax season, our team is here to help.

Disclaimer: This article is for informational purposes only and does not constitute legal or tax advice. Please consult your CPA or tax advisor for guidance specific to your situation.