Key September 2025 Tax Deadlines for Individuals

As we approach the fall season in 2025, it's crucial for taxpayers to be informed about significant tax deadlines, particularly relating to tip reporting and estimated tax payments. This article aims to equip you with vital knowledge on safe harbor rules, how to avert penalties, and effective strategies for tax preparation in 2026.

Tax Planning for Fall 2025 and Beyond

Tax season can be smooth with proper planning. At Tax time 365, we offer virtual consultations across the United States to guide small business owners and individual taxpayers in maintaining compliance with tax regulations. Schedule a consultation with us to optimize your tax strategy.

September 10 - Tip Reporting Requirement

Employees earning tips of more than $20 in August are required to report these to their employer by September 10 using IRS Form 4070. Your employer is obliged to withhold FICA and income tax from your tips. In cases where your regular wages don't cover these withholdings, the uncollected amount will be noted in box 8 of your W-2 form, and you must settle this when filing your annual tax return.

Image 1

September 15 - Estimated Tax Payment Deadline

The third installment of individual estimated taxes for 2025 is due on September 15. The U.S. tax system operates on a "pay-as-you-earn" basis, facilitated through various methods such as:

  • Employee payroll withholding;

  • Retiree pension withholding;

  • Estimated tax payments for self-employed individuals and others with non-withheld income sources.

Failure to prepay a minimum amount, known as a safe harbor, can lead to an underpayment penalty. The penalty is the federal short-term rate plus 3%, calculated quarterly.

Image 2

To avoid penalties, federal tax law offers these safe harbor options:

  • Payments meeting or exceeding 90% of current year tax;

  • For prior year tax liabilities, payments equal to 100% (or 110% if your AGI exceeds $150,000/$75,000 if married filing separately).

Real-Life Application:

If you owe $10,000 for the year and have prepayments of $5,600, you might face a penalty since your prepayments did not meet 90% of the current tax liability, which is $9,000. However, if your prior year's tax was $5,000, your $5,600 prepayment exceeds 110% of your previous year's tax ($5,500), qualifying you for safe harbor protection.

Ensure your prepayments adequately match your income changes, especially with substantial gains from capital transactions, bonuses, or retirement. Timeliness of each installment payment is crucial. Should you have questions regarding your estimates, don't hesitate to reach out to Tax time 365.

Note: State-level de minimis and safe harbor estimates may differ from federal guidelines. Contact us for state-specific advice.

Considerations for Weekends & Holidays

If a due date coincides with a Saturday, Sunday, or legal holiday, it extends to the next business day that isn’t a holiday. Disaster Area Extensions: In areas declared as disaster zones, filing deadlines are extended. Verify if your region qualifies by visiting FEMA and IRS websites.

Stay informed and strategic about your tax responsibilities to minimize stress and maximize compliance.

Share this article...

Want tax & accounting tips and insights?

Sign up for our newsletter.

I confirm this is a service inquiry and not an advertising message or solicitation. By clicking “Submit”, I acknowledge and agree to the creation of an account and to the and .

Social Media

Contact

(Mailing Address Only)
32158 Camino Capistrano A353
San Juan Capistrano, California 92675
(707) 733-3465 (Northern California)
Monday - Friday 9am-5pm
FAQs Frequently Asked Questions
Type your question here.
Please fill out the form and our team will get back to you shortly The form was sent successfully