Here is the reality most owners learn the hard way: almost every move that lowers your 2026 tax bill has to happen before December 31, not when you file next spring. A focused review in the fall beats a January scramble, and it is the difference between reacting to your taxes and actually planning them.

Use the checklist below to get ahead of the deadlines. It builds on the mid-year tax moves we covered earlier this year, now with a year-end lens.

Why Start Year-End Planning in the Fall

Most tax-saving strategies need time to execute. Buying equipment, funding a retirement plan, adjusting your salary, or timing a large invoice all take planning, and some have hard cutoffs at year end. Starting in the fall gives you room to act while the options are still open. Wait until you file and most of those doors are already closed.

Your Year-End Checklist

1. Review your year-to-date profit. Know roughly where your net income will land so you can estimate your liability and avoid surprises.
2. Check your estimated tax payments. Your final 2026 quarterly payment is due January 15, 2027. Make sure you are on track to avoid underpayment penalties.
3. Time income and expenses. Where it fits your cash flow, you may be able to defer income or accelerate deductible expenses into the year that helps you most.
4. Make needed equipment purchases. If you were going to buy equipment anyway, doing it before year end may allow a large first-year deduction. Verify current Section 179 and bonus depreciation limits, which changed under recent federal law.
5. Fund retirement plans. Contributing to a SEP-IRA, Solo 401(k), or similar plan can lower taxable income while building your own savings. Some plans must be set up before year end.
6. Revisit your entity and salary. If you run an S-corp, confirm your reasonable salary and distributions are set correctly. Not sure your structure still fits? See our guide on S-corp vs. LLC.
7. Clean up your books. Reconcile accounts, categorize transactions, and chase down missing receipts now, not in April. Behind on the books? Our bookkeeping team can help.
8. Gather 1099 information. Collect W-9s from contractors now so you can issue 1099s by the January 31, 2027 deadline.
9. Organize storm and casualty records. After an active hurricane season, keep documentation of any losses. See our hurricane records and casualty loss guide.
10. Meet with your CPA before December 31. A short planning session now can surface moves that are impossible to make once the year closes.

Key Dates to Put on Your Calendar

September 15, 2026

What is due: Extended S-corp and partnership returns for the 2025 tax year, plus the Q3 estimated tax payment.

October 15, 2026

What is due: Extended individual and C-corp returns for the 2025 tax year.

December 31, 2026

What is due: Deadline for most year-end tax-saving moves.

January 15, 2027

What is due: Final 2026 quarterly estimated tax payment.

January 31, 2027

What is due: 1099s and W-2s due to recipients.

Want a year-end plan built for your business?

Levine CPA and Advisors helps Miami owners find and act on savings before the year closes. Call (305) 912-0085 or book a year-end review.

Do Not Forget Compliance

Year-end is also the time to make sure you are current on filings and payments so you head into the new year clean. Payroll filings, sales tax, and estimated payments all have their own schedules. Our tax compliance team can make sure nothing slips through, and our tax planning services turn the checklist above into a concrete plan.

Frequently Asked Questions

When should I start year-end tax planning?

Ideally in the fall. Most tax-saving moves, from equipment purchases to retirement contributions to income timing, need to be completed before December 31, so starting early gives you time to act while the options are still open.

What is the deadline for year-end tax moves?

Most business tax-saving strategies must be in place by December 31, 2026 to count for the 2026 tax year. A few items, like certain retirement contributions, have later deadlines, so confirm each one with your CPA.

When is my last estimated tax payment for 2026 due?

The fourth-quarter estimated payment for the 2026 tax year is generally due January 15, 2027. Paying enough on time helps you avoid underpayment penalties.

Can I still lower my 2026 taxes in December?

Often yes. December is your last window for many moves, such as timing income and expenses, buying needed equipment, or funding certain plans. The earlier you plan, the more options remain, so do not wait until you file.

Do I need to send 1099s to my contractors?

If you paid qualifying contractors during the year, you generally must send 1099s by January 31, 2027. Collect W-9s now so you have the information ready.

This article is general information, not tax advice. Deadlines, limits, and rules change and depend on your situation. Verify current figures and consult a qualified CPA before acting.

Close out 2026 the smart way

Levine CPA and Advisors serves businesses across Miami and South Florida. Call (305) 912-0085 or contact us to schedule your year-end planning session.

‍