2026 Year-End Tax Checklist for Small Businesses: 10 Moves Before December 31

December 31 is not just the end of the year — it is the end of your chance to change your 2026 tax bill. Most tax planning happens before the year closes; filing season is just reporting what already happened. With about two months left, here is the year-end tax checklist for small businesses that actually moves the needle.

## 1. Reconcile your books through today — not in January

Clean books are the foundation of every other move on this list. Reconcile every bank and credit card account, categorize expenses, and chase down missing receipts now. Planning on messy numbers is guessing, and your CPA cannot find deductions in a shoebox of unclassified transactions.

If your books are behind, this is also the moment to fix that — before year-end close turns a catch-up project into a filing-season crisis.

## 2. Run a 2026 tax projection before you make any moves

Do not buy equipment or prepay expenses on a hunch. A quick projection of 2026 income tells you whether you need deductions this year or would rather push income into next year. The same purchase can be smart in one tax bracket and wasted in another.

## 3. Get W-9s from every contractor now

You will owe 1099-NEC forms for contractors you paid during 2026, and those forms are due February 1, 2027 (January 31 falls on a Sunday, so the deadline moves to the next business day). Collecting W-9s in January, when contractors are slow to reply, is how penalties happen. Collect them now, while everyone is still reachable.

## 4. Max out retirement contributions — watch the December 31 line

For 401(k) plans, employee salary deferrals generally must run through payroll by December 31, 2026 (the 2026 employee limit is $24,500, with additional catch-up amounts for savers age 50 and over). S corporation owners: check that your salary and deferrals are on track before the last payroll of the year runs.

SEP IRA and solo 401(k) employer contributions, by contrast, can generally wait until your tax filing deadline — but the plan itself must exist by December 31. Do not assume; confirm your plan's rules with your advisor.

## 5. Place equipment in service by December 31

Business equipment, vehicles, and software only count for 2026 if they are placed in service by December 31 — ordering is not enough. If a purchase was already planned for early next year, pulling it into December can accelerate the deduction. If it was not planned at all, do not buy it just for the tax break.

## 6. Check S corporation owner salaries

If your business is an S corporation, the IRS expects owner-employees to take a reasonable salary before taking distributions. Year-end is the time to review whether salary, payroll taxes, and health insurance reported on the W-2 are where they should be — not something to discover during return preparation.

## 7. Plan your Q4 estimated tax payment

Your fourth-quarter estimated tax payment for 2026 is due January 15, 2027. If income spiked late in the year, that payment needs to reflect it, or underpayment penalties follow. Note that if you file your full 2026 return and pay in full by early February, you may be able to skip the January payment — confirm the rule for your situation before relying on it.

## 8. Review charitable giving and year-end gifts

Charitable gifts must be made by December 31 to count for 2026, and the rules for what counts changed this year — including new limits on deductions for itemizers and a limited deduction for non-itemizers. Keep receipts and acknowledgment letters with your tax file; a gift without documentation is a deduction you cannot defend.

## 9. Tidy up payroll and year-end forms

W-2s for employees are also due February 1, 2027, on the same weekend-shift rule as 1099-NECs. Verify employee addresses, confirm final payroll totals, and make sure bonuses and fringe benefits are recorded before the last payroll closes the year.

## 10. Book your January CPA meeting now

The best time to talk to your CPA about 2026 is not April — it is January, while there is still time to fund retirement contributions, finalize estimates, and fix anything the projection uncovered. CPAs' January calendars fill fast; the businesses that plan early are the ones that file calmly.

## The bottom line

Year-end tax planning is a short list done early, not a long list done in a panic. Reconcile, project, collect forms, fund retirement, and handle the December 31 deadlines — then let filing season be paperwork, not firefighting.

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