Resources

Businesses – Partnerships (including LLCs), C Corps (Form 1120), and S Corps (Form 1120S)

January 15, 2025 – 4th Quarter 2024 estimated tax payment due

Early 2025 – 2024 Tax season begins

January 31, 2025 – Employers send W-2s forms to employees

January 31, 2025 – Send certain 1099 forms

March 15, 2025 – Taxes are due for some business types (partnerships, multi-member LLCs, and S-Corporations). Businesses organized as partnerships, including multi-member LLCs, and S-Corporations need to file Form 1065, or 1120S by March 15, 2025, if they are a calendar year business. If your business uses a fiscal year, you need to file your tax return by the 15th day of the third month following the close of your tax year. For example, if your business uses an April 1 – March 31 tax year, your business tax return would be due June 15 instead of March 15.

April 15, 2025 – Taxes for C-Corporations are due. Businesses organized as C-Corporations need to file form 1120 by April 15, 2025, if they are a calendar year business. If your business uses a fiscal year, you need to file your tax return by the 15th day of the third month following the close of your tax year. For example, if your business uses an April 1 – March 31 tax year, your business tax return would be due June 15 instead of in April.

September 15, 2025 – Deadline for extended partnership and S-corporation returns

October 15, 2025 – Deadline for extended C-corporation returns

January 15, 2026 – Fourth quarter 2025 estimated tax payment due

The above doesn’t cover every tax deadline, merely the most important ones broadly relevant to these groups of taxpayers. For a comprehensive view of all the important tax deadlines applicable to each taxpayer, please visit IRS Publication 509.