Year-End Tax Planning Checklist for Individuals and Business Owners (2026 Guide)

Most people don't think about their taxes until January of the filing year. However, by the time your tax documents show up in your mailbox, most of your 2026 tax bill is already locked in. 

The actions that change your outcome— retirement contributions, entity elections, income timing, and expense tracking— have hard deadlines that you need to account for before December 31st.

Whether you're an individual filer or a business owner across New York, New Jersey, or Connecticut, unless you want to scramble come tax season, there are several things you should do before year-end.

Why Fall is the Right Time for Tax Planning

Although autumn tends to be pretty busy with school starting back up and the impending holiday season, there are three main reasons why it's also the perfect time to get a jump start on your tax planning.

1. You Give Yourself Time: Many tax planning strategies take weeks to execute. Starting early gives you enough runway to get them done.

2. Your Finances are Predictable: By September/October, you have a pretty accurate idea of what your full-year income is going to look like, so you can predict your tax liability and course correct where necessary.

3. You Can Account for Multi-State Deadlines: New York, New Jersey, and Connecticut each have their own estimated tax due dates and business tax deadlines that don't always mirror the federal calendar. Early planning avoids last-minute surprises at the state level.

Having an early check-in with your CPA makes a big difference between simply filing your taxes and truly optimizing your tax strategy.

As you get that head start, here are some things you'll want to take advantage of and plan for.

Year-End Tax Checklist for Individuals

As an individual filer, take these three tax planning steps before the year’s end.

1. Maximize Retirement Contributions Before the Deadline

The IRS increased limits on retirement contributions to $24,500 for 401(k)s and $7,500 for IRAs. 

Workers over 50 can also add an additional $8,000 catch-up contribution to their 401(k), while those aged 60 to 63 can add “super catch-up” contributions of $11,250. Account holders over 50 can also contribute an additional $1,100 to their IRA. If you are a high earner bringing in over $150,000 per year, you have to make those catch-up contributions on a Roth basis (after tax).

Action Item: See how your payroll deferrals are pacing against your contribution limit. There are only a few pay periods left to adjust so you can max out your retirement contributions.

2. Decide Between Itemizing and the Standard Deduction

The IRS increased the 2026 standard deduction as part of its broader inflation adjustments. If you have yet to claim them, you may have the option to bunch certain deductions, like charitable gifts or elective medical expenses, into one calendar year so you clear the standard deduction threshold and can itemize for that tax year.

Action Item: Run a quick projection to see if your itemized deductions come close to the standard deduction. If they do, it may be worth making a charitable donation this year to change up your deduction strategy.

3. Tally Up Withholding and Estimated Tax Payments

Even if the general filing season isn't until April, Q4 estimated tax payments hit right at the start of the year. If you earn income across state lines or through remote work, not withholding enough to the correct tax body can land you with a surprise bill. The same goes for setting aside estimated taxes as a contractor or 1099 worker.

Action Item: Double-check each state’s withholding allocations and your estimated tax liability to ensure you’re paying what you owe come tax season.

Year-End Tax Checklist for Business Owners

If you're a business owner in the Tri-State area, here are tax planning tasks to complete before December ends.

1. Revisit Your Entity Structure and Elections

Your entity structure (S-corp, C-corp, or LLC) and the corresponding taxation need to match your current income levels and 2026 bracket environment. If your income reaches S-Corp level, there are strict deadlines to elect this status that can't be done retroactively.

Action Item: Review your income and structure to make sure you're operating as the correct type of business and meeting proper tax liabilities.

2. Time Income and Expenses Strategically

Depending on your operating costs and income, it may be worth accelerating deductible expenses, like prepaying rent or insurance and stocking up on supplies, or deferring invoicing income to January to lower your tax liability.

Action Item: Go over these figures with a trusted CPA, as this only works well if you're able to accurately project multiple years of income.

3. Review Depreciation and Equipment Purchase Timing

Although you can claim depreciation and expenses that come from assets you need to operate, that only applies if the asset is placed in service by the end of the year. Simply purchasing it before December 31st does not make it eligible under Section 179.

Action Item: If you're planning a major equipment purchase for early 2027, evaluate whether moving it up into Q4 2026 makes tax sense.

4. Run a Multistate Compliance Check (NY / NJ / CT)

NY, NJ, and CT have their own independent estimated tax and business entity tax deadlines. If you operate with employees, inventory, or sales crossing state lines, you may trigger new Nexus filing obligations without realizing it.

Action Item: Review your sales and use tax exposure to avoid receiving penalties for incorrect multi-state business operations.

Jump Start Your Tax Planning with AVM DeMars

These checklists are a starting point. The real value in devising an effective tax strategy comes from applying them your specific numbers—and you shouldn’t do it alone.

The tax advocacy team at AVM DeMars brings combined decades of multi-state experience across New York, New Jersey, and Connecticut as well as direct experience representing our clients before the IRS and state tax departments.

Don't wait until the last minute to start thinking about your tax strategy. Schedule a tax planning consultation with our team today.