September 2026 Individual Tax Deadlines and Estimated Payments
As we head into fall, it is an ideal time to review your 2026 tax situation and begin planning for 2027. With a major estimated tax payment due this month, now is the perfect opportunity to assess your income, withholdings, and payments to determine if you need to make any adjustments before year-end. Whether you are a growing small business owner in North Carolina or a dual-income professional, proactive planning is key to keeping more of what you earn. If you want to review your financial picture, reach out to our team at Bly Business Accounting to schedule a tax planning consultation.
September 10 Deadline for Reporting Tips
If you are an employee who works for tips and received more than $20 in tips during August, you must report that income to your employer no later than September 10. You can submit this using IRS Form 4070 or provide your own signed statement that includes your name, address, Social Security number, employer or establishment name and address, the specific period covered, and the total tips received.
Once reported, your employer is required to withhold FICA and income taxes on those tips from your regular wages. If your regular paycheck is not large enough to cover the necessary withholding, your employer will report the uncollected amount in box 8 of your W-2 at year-end. You will then be responsible for paying that uncollected withholding when you file your annual return.
September 15 Deadline for Estimated Tax Payments
The third installment of 2026 individual estimated taxes is due on September 15. The federal tax system operates on a "pay-as-you-earn" basis, meaning taxes must be paid as income is earned or received during the year. The government facilitates this through payroll withholding for employees, pension withholding for retirees, and estimated tax payments for self-employed individuals and those with other income sources not covered by withholding.
When taxpayers fail to prepay a required minimum amount—known as a safe harbor—they can face an underpayment penalty. The IRS calculates this penalty quarter-by-quarter, setting the rate at the federal short-term rate plus 3 percentage points.
Avoiding Underpayment Penalties with Safe Harbors
Federal tax law provides specific mechanisms to help you avoid underpayment penalties. First, if your total underpayment is less than $1,000 (the de minimis amount), the IRS will not assess a penalty. Beyond that, the law offers two primary safe harbor prepayments:
The Current Year Safe Harbor: If your total payments equal or exceed 90% of the tax owed in the current year, you avoid the penalty.
The Prior Year Safe Harbor: Alternatively, you can avoid penalties by paying 100% of your prior year's tax liability. However, for taxpayers whose Adjusted Gross Income (AGI) exceeds $150,000—or $75,000 for married taxpayers filing separately—the prior year's safe harbor requirement increases to 110%.
Safe Harbor Calculation Example
Suppose your total tax for the current year is $10,000, and your prepayments total $5,600, leaving you with an additional $4,400 owed on your tax return. To determine if a penalty applies, you first look at the 90% safe harbor exception. Since 90% of $10,000 is $9,000, your $5,600 prepayment falls short, meaning you cannot avoid the penalty under this first exception.
However, the second safe harbor may still protect you. Assume your prior year's tax was $5,000. Because your $5,600 prepayment is greater than 110% of that prior year’s tax ($5,500), you successfully qualify for this safe harbor and escape the penalty entirely.
Why Prepayment Accuracy Matters
The safe harbor rules underscore the importance of ensuring your prepayments are adequate, particularly if you experience a substantial increase in income. Sudden income spikes commonly occur from the sale of stocks or property, the receipt of large bonuses, or when a taxpayer enters retirement. Meeting the safe harbor exception also requires making each required estimated tax installment on time. If you have questions regarding your safe harbor estimates, please call our office as soon as possible.
CAUTION: It is crucial to remember that state rules can differ significantly from federal guidelines. De minimis amounts, safe harbor estimate rules, and estimated payment due dates vary by state. Please call this office for guidance on your particular state's safe harbor rules.
Navigating Weekends, Holidays, and Disaster Extensions
Federal tax deadlines follow a standard adjustment rule: if a due date falls on a Saturday, Sunday, or legal holiday, the deadline is automatically extended to the next business day that is not a legal holiday.
Additionally, when a geographical area is formally designated as a disaster area, tax due dates are typically extended to provide relief. To check if your area has received a disaster designation and to view specific filing extension dates, visit the following agency websites:
Take Control of Your Fall Tax Strategy
Staying ahead of individual due dates and understanding how safe harbor rules apply to your unique situation can save you from unnecessary stress and costly IRS penalties. By reviewing your financial picture now, you can keep more capital working toward the growth of your business.
If you have questions about your estimated tax payments or want to implement strategies to simplify your tax situation, schedule a consultation with Samuel Bly and our team at Bly Business Accounting today.
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