September 15 Tax Deadline: What Business Owners Need to Know
September is an important month for many business owners when it comes to taxes. While April is the deadline most people are familiar with, September 15 is another important date to keep on your radar.
For many business owners, it marks the third estimated tax payment deadline of the year. It can also be a filing deadline for certain businesses that received an extension on their previous tax return.
Understanding what the September 15 tax deadline means and whether it applies to you can help you stay ahead of your tax obligations and avoid unnecessary surprises.
Who Has a September 15 Tax Deadline?
September 15 is generally the third estimated tax payment deadline for individuals and corporations that make estimated tax payments throughout the year.
For business owners, this can include individuals who receive income through a sole proprietorship, partnership, or S Corporation and do not have enough tax withheld from their income.
Estimated tax payments allow you to pay taxes throughout the year rather than waiting until your tax return is filed. The amount you need to pay depends on factors such as your income, deductions, credits, and other sources of taxable income.
September 15 can also be an important filing deadline for calendar year partnerships and S Corporations that requested an extension on their 2025 tax returns. If an extension applies to your business, this is generally the deadline for filing those returns.
Not every business owner will have a payment or filing due on September 15, which is why understanding your specific tax situation is so important.
Are Your Estimated Tax Payments Still on Track?
If you make quarterly estimated tax payments, September is a good time to review whether those payments still reflect your current financial situation.
Your business may look very different now than it did earlier in the year. Revenue may have increased, expenses may have changed, or you may have taken on new clients, employees, or projects.
All of these changes can affect your expected tax liability.
Instead of simply making the same payment you made last quarter, take a closer look at your year-to-date numbers. Reviewing your current income and expenses can help you determine whether your estimated payments are still on track and what you may need to plan for during the rest of the year.
Why September Is a Good Time for Tax Planning
The September 15 deadline also serves as a good reminder that small business tax planning should happen throughout the year.
By September, you have several months of financial information available, but there is still time to make certain decisions before the end of the year.
Business owners may want to review:
- Revenue and profitability
- Estimated tax payments
- Business expenses
- Retirement contributions
- Major purchases
- Business structure and entity elections
- Bookkeeping and financial records
Looking at these areas now can help you make informed decisions while there is still time to plan instead of waiting until tax season.
Don't Wait Until Tax Season to Look Ahead
Tax preparation focuses on reporting what already happened. Tax planning gives you the opportunity to make decisions before the year is over.
At Blueprint Tax Advisors, we believe business owners benefit from having a tax strategy that goes beyond filing a return. Our approach looks at your income, expenses, estimated payments, entity structure, retirement strategies, and long-term goals to help build a plan around your business.
For business owners in Conway and throughout Central Arkansas, September can be a valuable checkpoint to review your numbers and prepare for the months ahead.
If you are unsure whether the September 15 deadline applies to you or want to make sure your estimated tax payments are on track, schedule a consultation with Blueprint Tax Advisors to build a tax strategy designed around your business and your goals.