What Small Business Owners Must Know About Tax Deadlines for 2025

As a small business owner, understanding tax deadlines is crucial for staying compliant with federal, state, and local tax laws. Missing tax deadlines can result in penalties, interest, and even damage to your business’s reputation. In 2025, small business owners must be aware of a variety of key tax deadlines, including those related to income tax, payroll taxes, estimated taxes, and other business-specific filings. This article provides a detailed guide to help small business owners navigate tax deadlines in 2025.

Key Tax Deadlines for Small Businesses in 2025

1. Income Tax Deadlines

Income taxes for small businesses are typically due based on the structure of the business (sole proprietorship, partnership, S-corp, C-corp). Here's what you need to know:

Sole Proprietorships, Partnerships, and S-Corporations

March 15, 2025: Partnerships (Form 1065) and S-corporations (Form 1120S) must file their income tax returns by this date. These businesses do not pay tax directly but instead pass their profits or losses onto the owners, who report them on their personal tax returns.
April 15, 2025: Sole proprietorships file their tax returns using Form 1040 and Schedule C, which are due by this date. Since sole proprietors are considered self-employed, they will report their business income and expenses directly on their individual return.

Note: If any of these dates fall on a weekend or holiday, the deadline is generally extended to the next business day.

April 15, 2025: C-corporations must file their income tax return using Form 1120. C-corps are separate taxable entities and are taxed independently from their owners.

Tax Extensions

If a business cannot meet the tax deadline, it can apply for an automatic extension. For example, Sole Proprietorships, Partnerships, and S-Corporations can file Form 7004 to extend the deadline by six months to September 15, 2025. Similarly, C-Corporations can file Form 7004 to extend their filing deadline to October 15, 2025.

2. Estimated Quarterly Tax Deadlines

Most small business owners, especially sole proprietors and partners, need to pay estimated taxes throughout the year. These quarterly payments help businesses avoid penalties for underpayment when filing annual tax returns.

Q1 Payment Due Date: April 15, 2025
Q2 Payment Due Date: June 16, 2025
Q3 Payment Due Date: September 15, 2025
Q4 Payment Due Date: January 15, 2026 (Note: This is the payment deadline for the fourth quarter of 2025.)

Who Needs to Pay Estimated Taxes?

If you expect to owe at least $1,000 in taxes after subtracting your withholding and refundable credits, you are generally required to make estimated tax payments. This includes sole proprietors, partners, and shareholders in S-corporations who receive income that isn’t subject to automatic withholding (like wages).

3. Payroll Tax Deadlines

Small business owners who have employees must be aware of payroll tax deadlines. Payroll taxes include federal income tax withholding, Social Security and Medicare taxes, and federal unemployment tax (FUTA). These taxes need to be deposited and reported periodically.

Payroll Tax Deposit Deadlines:

The IRS requires businesses to deposit payroll taxes on a semi-weekly or monthly basis, depending on the size of the business’s payroll. These deposits are generally due by:

The 15th and the last day of each month for semi-weekly depositors.
The 15th of the next month for monthly depositors.

For example:

January 2025 deposits are due by January 31, 2025.

Quarterly Payroll Tax Filing (Form 941):

April 30, 2025: Form 941, the Employer's Quarterly Federal Tax Return, must be filed for the first quarter of 2025. This form reports wages, tips, and other compensation, as well as the taxes withheld.
July 31, 2025: For the second quarter, the deadline to file Form 941 is July 31, 2025.
October 31, 2025: For the third quarter, the deadline is October 31, 2025.
January 31, 2026: The fourth-quarter return must be filed by January 31, 2026.

4. State and Local Tax Deadlines

State and local tax deadlines may differ from federal deadlines, so it’s essential for small business owners to be aware of the specific tax requirements in their state or locality. Many states require quarterly estimated income tax payments, and businesses are also often subject to sales tax, property tax, and state unemployment tax (SUTA) deadlines.

Sales and Use Tax Deadlines

Most states require businesses to file sales tax returns on a monthly, quarterly, or annual basis, depending on the volume of sales.
Sales tax deadlines usually fall on the 20th of the month following the reporting period. For example, the sales tax for the month of January 2025 is typically due on February 20, 2025.

State Income Tax Deadlines

States with income taxes have their own filing deadlines, which may align with federal tax deadlines or vary slightly. Ensure you know your state’s filing schedule for business income taxes.

5. Other Important Tax Deadlines

Form 1099 Filing Deadlines

January 31, 2025: If you’ve paid contractors $600 or more during the year, you must issue Form 1099-NEC by January 31, 2025. This form reports non-employee compensation.
February 28, 2025: If you’re filing Form 1099 by paper, it’s due by February 28, 2025.
March 31, 2025: If filing Form 1099 electronically, the deadline is March 31, 2025.

Corporate Tax Filing (Form 1120)

April 15, 2025: The deadline for C-corporations to file Form 1120, which is the U.S. Corporation Income Tax Return.

Conclusion

Staying on top of tax deadlines is essential for small business owners to avoid penalties, maintain good standing with the IRS, and ensure accurate financial reporting. In 2025, small business owners must keep track of key dates, including income tax, payroll tax, and estimated quarterly tax deadlines. Additionally, remember to file and pay sales taxes and other state-specific taxes on time.

By staying organized and planning ahead, small business owners can avoid unnecessary stress and keep their businesses on track throughout the year. Consider consulting with a tax professional to ensure that you’re compliant with all federal, state, and local tax obligations in 2025.