September Tax Check-In: 7 Things to Review Before the End of the Year

September 7th, 2026 | TaxOne Financial

Tax season may still feel months away, but September is one of the best times to take a closer look at your tax situation.

Why?

Because there is still time left in the year to make adjustments.

Waiting until you file your tax return to think about taxes can mean discovering a larger-than-expected balance when many planning opportunities have already passed.

Whether you're an employee, self-employed, or a business owner, here are seven things worth reviewing before the end of 2026.

1. Review Your Income So Far

Has anything changed with your income this year?

Maybe you received a raise, changed jobs, started a side business, began freelancing, sold investments, or your business is having a stronger year than expected.

Changes in income can affect your overall tax situation.

Take a look at how much you've earned so far and what you reasonably expect to earn through December. A clearer picture now can help you determine whether adjustments may be necessary before year-end.

2. Check Your Federal Tax Withholding

If you're a W-2 employee, don't automatically assume the amount being withheld from your paycheck will be enough to cover your tax liability.

This is especially important if you:

• Changed jobs during the year

• Have multiple sources of income

• Work more than one job

• Received a significant raise or bonus

• Have a spouse who also works

• Started earning self-employment or side-business income

September still gives you time to review your withholding and, when appropriate, adjust your Form W-4 for the remaining pay periods of the year.

The goal isn't necessarily to receive the largest refund possible. It's to avoid unnecessary surprises when you file.

3. Make Sure Your Quarterly Estimated Taxes Are on Track

If you're self-employed, an independent contractor, a business owner, or receive income that doesn't have enough tax withheld, you may need to make estimated tax payments throughout the year.

The third estimated tax payment deadline for 2026 is September 15, 2026.

Instead of simply paying the same amount every quarter without reviewing your numbers, compare your estimated payments with your actual year-to-date income.

If your income has increased significantly, your original estimates may no longer reflect your current tax situation.

Likewise, if income has decreased, it may be worth reviewing whether your remaining estimated payments should be adjusted.

4. Business Owners: Review Your Year-to-Date Profit

Revenue tells you how much money came into your business. Profit gives you a much better picture of what may ultimately affect your taxes.

By September, business owners should have a reasonably clear view of how the year is developing.

Review your:

• Year-to-date revenue

• Business expenses

• Net profit

• Estimated tax payments

• Payroll, if applicable

• Expected income and expenses for the remainder of the year

This is also a good time to identify missing expenses or bookkeeping issues rather than trying to reconstruct an entire year of financial activity during tax season.

5. Get Your Bookkeeping Caught Up

If your bookkeeping is several months behind, now is the time to address it.

Waiting until January or February can make tax preparation more stressful and may leave you making important business decisions without accurate financial information.

Make sure your accounts are reconciled and review your transactions for items such as:

• Business expenses that haven't been categorized

• Personal expenses mixed into business accounts

• Duplicate transactions

• Missing income

• Contractor payments

• Equipment or major business purchases

• Business mileage and other records that may need documentation

Clean books aren't just useful for preparing a tax return. They can also help you understand how your business is actually performing.

6. Start Year-End Tax Planning Before Year-End

One of the biggest misconceptions about taxes is that tax planning happens during tax season.

By the time you're preparing your return, you're primarily reporting transactions and decisions that already occurred.

Tax planning happens before the year ends.

Depending on your individual circumstances, a year-end tax review may include evaluating retirement contributions, business expenses, estimated tax payments, income timing, deductions, and other available tax strategies.

There isn't one strategy that works for every taxpayer. That's why planning should be based on your actual income, business activity, goals, and overall tax situation.

The important part is having the conversation while there is still time to make informed decisions.

7. Don't Carry Unresolved IRS Issues Into Another Tax Season

If you have unfiled tax returns, an outstanding IRS balance, unanswered notices, or another unresolved tax issue, don't wait for the next filing season to begin addressing it.

Start by understanding exactly where you stand.

Depending on your situation, potential resolution options may include payment arrangements, penalty relief, or other IRS resolution strategies.

The appropriate solution depends on your specific circumstances, but taking action sooner gives you more time to understand your options and develop a plan.

Don't Wait Until Tax Season to Think About Taxes

Your tax return tells the story of what already happened.

Tax planning allows you to make informed decisions while there's still time to act.

September is a great time to review your income, withholding, estimated payments, business finances, bookkeeping, and any unresolved tax matters so you can enter the final months of 2026 with a clearer picture.

Ready for a Tax Check-In?

Don't wait until tax season to find out where you stand.

TaxOne Financial, located in Tamarac, Florida, helps individuals and business owners throughout Broward County and South Florida with tax preparation, proactive tax planning, quarterly estimated taxes, bookkeeping, business tax services, and IRS tax resolution.

Schedule a consultation today, and let's review your tax situation before the end of the year.

This article is for general informational purposes only and should not be considered individualized tax advice. Tax laws and strategies vary based on each taxpayer's circumstances.