Key September 2025 Tax Deadlines for Individuals

As we approach September 2025, it's crucial to stay informed about significant tax deadlines, including tip reporting and estimated tax payments. Understanding the safe harbor rules, avoiding penalties, and planning strategical tax strategies for 2026 are essential objectives for savvy taxpayers.

Tax Planning for Fall 2025 and 2026
Contact Haley Claypool & Associates to schedule a consultation appointment to ensure your tax planning strategy is robust and effective.

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September 10 - Mandatory Tip Reporting
Employees earning over $20 in tips during August must report them to their employer using IRS Form 4070 by September 10. Employers are required to withhold applicable FICA taxes and income tax withholdings from your regular wages. Should your wages be insufficient to cover the withholding, your employer will note the uncollected amount in box 8 of your annual W-2. This amount must be settled when you file your annual return.

September 15 - Estimated Tax Payments Due
The third installment of your 2025 estimated tax payments is due. Our tax framework operates on a "pay-as-you-earn" system, supported by several mechanisms:

  • Payroll withholding for employees

  • Pension withholding for retirees

  • Estimated tax payments for self-employed individuals and other income sources not accounted for by withholding

Failure to meet the safe harbor prepayments may result in underpayment penalties. These penalties tally up as the federal short-term rate plus 3 percentage points, assessed quarterly.

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To avoid such penalties, consider two primary safe harbor prepayment methods:

  • Paying at least 90% of your current year's tax liability

  • Paying 100% of the previous year’s tax liability (110% for AGI over $150,000 or $75,000 for separate filers)

Example: If your 2025 tax is $10,000 and your prepayments total $5,600, you will owe $4,400. Under the first safe harbor rule, because 90% of $10,000 is $9,000, you fall short. However, if your prior year’s tax was $5,000 and your prepayments hit $5,600 (which is more than 110% of $5,000), you meet the second safe harbor, avoiding penalties.

This example highlights why adequate prepayments are vital, especially amid significant income jumps, such as asset sales, bonuses, or retirement income shifts. Timely estimated tax payments are necessary to benefit from safe harbor exceptions. For personalized advice on your safe harbor estimates, reach out to our office promptly.

Milestones & Cautions:

  • If due dates fall on weekends or legal holidays, they roll over to the next business day.

  • State de minimis amounts and safe harbor rules might differ—verify with this office.

Disaster Area Extensions
When disasters strike and areas are declared emergency zones, filing deadlines extend correspondingly. For confirmation of a disaster zone status and new filing dates, visit:

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