Q3 Tax Planning Checklist: What Small Business Owners Should Do Right Now

Most small business owners think about taxes twice a year: when they're due, and when they hurt. But the business owners who consistently pay less in taxes — legally — are the ones who plan throughout the year, not just in April.

Q3 (July through September) is one of the most important windows for tax planning. You still have time to make meaningful changes before December 31st. Here's what you should be reviewing right now.

1. Review Your Year-to-Date Income and Expenses

Pull your Q1–Q3 profit and loss statement and compare it to last year. Ask yourself:

• Are you tracking ahead of, behind, or even with last year?
• Are there any large expenses coming in Q4 that you could accelerate into this year?
• Are there deductions you've been sloppy about tracking — mileage, home office, meals?

This snapshot tells you whether your estimated tax payments are on track, and whether you should be looking to accelerate deductions or defer income.

2. Check Your Estimated Tax Payments

If you're self-employed or own a business, you're required to pay estimated taxes quarterly. The Q3 estimated tax payment is due September 15, 2026.

To calculate what you owe, look at your year-to-date net income and apply your effective tax rate. If you're unsure, this is exactly the kind of calculation we handle for our clients at Shuniyaa Financial.

3. Maximize Retirement Contributions

One of the most powerful tax-reduction tools for small business owners is a retirement account. The contributions you make reduce your taxable income dollar-for-dollar.

• SEP-IRA: Contribute up to 25% of net self-employment income (max $69,000 for 2026)
• Solo 401(k): Employee + employer contributions, up to $69,000 combined
• SIMPLE IRA: Good for businesses with employees — up to $16,000 employee deferral

If you don't have a retirement plan set up yet, Q3 is an ideal time — Solo 401(k)s must be established by December 31st to count for the current tax year.

4. Review Your Business Structure

Are you still operating as a sole proprietor or single-member LLC? If your net profit is consistently above $60,000–$80,000, an S-Corporation election could save you significant self-employment taxes.

The deadline to elect S-Corp status for the current tax year is typically March 15th, but planning now gives you time to model the numbers, set up payroll, and make the switch at the right moment.

5. Plan Major Purchases Before Year-End

If your business needs new equipment, vehicles, computers, or software — buy before December 31st. Under Section 179, you can deduct the full cost of qualifying assets in the year of purchase rather than depreciating them over years.

For 2026, the Section 179 deduction limit is $1,220,000. This is a major opportunity for businesses that need to invest in infrastructure.

6. Get Your Books Caught Up

You can't plan taxes accurately without accurate books. If your bookkeeping is behind — or if you're still doing it yourself in a spreadsheet — Q3 is the time to get current.

At Shuniyaa Financial, we work with business owners throughout the year to keep books clean, categorized, and ready for tax time. No more scrambling in March.

Don't Wait Until January

Tax planning is not a once-a-year event. The decisions you make in Q3 directly affect what you'll owe — or get back — in April. The business owners who work with an advisor throughout the year consistently come out ahead.

If you'd like to go through this checklist together and build a year-end plan specific to your business, we're here for it.

This article is for informational purposes only and does not constitute tax, legal, or financial advice. Please consult with a qualified tax professional for guidance specific to your situation.