Key September 2025 Tax Deadlines You Shouldn't Miss

Stay ahead of your tax obligations with our comprehensive guide to the vital tax deadlines this September. From reporting tips to making estimated tax payments, ensure you're fully informed and ready for 2026 planning. 

Image 1

2025 Fall and 2026 Tax Planning

Professional advice can make all the difference in your tax strategy. Contact our office today to set up a planning consultation tailored to your individual needs.

September 10 - Report Tips to Employer

If you earned more than $20 in tips during the month of August, remember to report these tips to your employer by September 10 using IRS Form 4070. Your employer will deduct FICA taxes and income tax withholding from your regular paycheck. In cases where regular wages aren’t enough to cover these deductions, the remaining uncollected amounts will be noted in box 8 on your W-2. You must pay this balance when you file your year's tax return.

Image 2

September 15 - Estimated Tax Payment Due

The third installment of your 2025 estimated taxes is due this September 15. As part of the "pay-as-you-earn" tax system, this payment is crucial for meeting your tax obligations, particularly for self-employed individuals or those with additional income streams not typically covered by withholding, like dividends or rental income.

The IRS provides several mechanisms to aid in compliance with this system, including:

  • Payroll withholding for employees
  • Pension withholding for retirees
  • Quarterly estimated tax payments for other income sources

Let's Chat!
If any of these topics caught your attention, please contact to start the conversation!
Contact Us

To avoid an underpayment penalty, it's essential to understand the "safe harbor" rules. For instance, as long as your prior year’s adjusted gross income did not exceed $150,000 (or $75,000 for those married filing separately), paying at least 110% of your previous year's tax liability typically satisfies safe harbor requirements.

Example: If your tax liability this year is $10,000, but you only prepaid $5,600, it’s useful to determine if safe harbor provisions apply. If previously your tax was $5,000, and you’ve prepaid $5,600, that's over 110% of last year's liability, allowing you to circumvent the penalty.

Image 3

Important Note: Certain states may have different de minimis amounts and safe harbor rules compared to federal requirements, so be sure to check with your state's specific guidelines.

Deadline Adjustments for Weekends & Holidays:

Remember that if a tax deadline falls on a weekend or federal holiday, it automatically shifts to the next business day that isn't a holiday. Extensions also apply for disaster-designated areas. For more information, you can visit FEMA's website or the IRS's tax relief page.

By staying aware of these essential deadlines and planning your tax strategies, you can avoid unexpected penalties and maintain financial health heading into 2026. For personalized help, feel free to call our office today!

Let's Chat!
If any of these topics caught your attention, please contact to start the conversation!
Contact Us
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 .