Most year-end tax content is a checklist of vague reminders. “Maximize your deductions.” “Review your withholdings.” “Consider charitable giving.”
That’s not planning. That’s a list of things to think about thinking about.
Here’s what year-end tax planning actually looks like for a small business owner — with enough specificity to be useful.
Start With Where You Actually Stand
Before you can make any intelligent year-end moves, you need to know two things. What your taxable income looks like right now. And what your tax liability is tracking toward based on that income.
If you don’t know these numbers, get them before you do anything else. Pull your year-to-date profit and loss from your accounting software. Add up your estimated tax payments made so far. Ask your accountant for a quick projection of where your liability is likely to land.
Everything else depends on this starting point. Without it you’re making decisions in the dark.
If Your Income Is Higher Than Expected
A better-than-expected year is good news for your business and creates planning opportunities worth acting on.
Retirement contributions are the most powerful lever most small business owners aren’t fully using. A solo 401k allows combined contributions of up to $72,000 in 2026 for owners under 50. Every dollar contributed is a dollar off your taxable income — which means savings on both federal income tax and self-employment tax. If you’ve been contributing less than the maximum, December 31 is the deadline for the employee contribution portion.
Equipment and asset purchases planned for early next year are worth pulling into this year if the numbers make sense. A piece of equipment you were going to buy in January gets the same Section 179 deduction if you buy it in December — except it reduces this year’s tax bill instead of next year’s. If you’re having a high-income year and a lower one is expected, the timing of that deduction matters.
Prepaying certain business expenses — software subscriptions, professional memberships, insurance premiums — for the following year may be deductible in the current year if you’re on cash basis accounting. This moves a deduction from next year into this year when your income is higher and the deduction is worth more.
Year-end moves need time to execute. Book a review while there are still weeks left on the calendar.
If Your Income Is Lower Than Expected
A slower year creates a different set of planning decisions.
If you’ve been making estimated payments based on prior-year income and this year is coming in significantly lower, you may be overpaying. The IRS doesn’t pay you interest on overpayments — they apply them to next year’s liability or refund them in April. If your business needs cash now, adjusting your Q4 payment downward based on your current-year projection is worth discussing with your accountant.
A lower-income year can also be a good time to consider a Roth conversion — moving money from a traditional IRA to a Roth IRA and paying tax on it now at a lower rate than you’d pay in a higher-income year. This isn’t relevant to everyone but for business owners with IRAs it’s a planning conversation worth having in low-income years.
S-Corp Owners — Specific Checklist
If you’re an S-Corp owner, year-end has some specific boxes to check.
Is your salary for the year reasonable? The IRS requires S-Corp owners to pay themselves a salary that reflects what the role would command in the open market. Too low a salary is an audit trigger. If you’ve been paying yourself significantly less than market rate, that’s worth reviewing before year end — and potentially before a future audit makes the question unavoidable.
Have your distributions been handled correctly? Distributions from an S-Corp are not subject to payroll taxes — but they need to be clearly separated from your salary and documented correctly. If you’ve been moving money from the business account to your personal account without clear documentation of what’s a distribution versus what’s a salary payment, clean that up before year end.
Is your basis sufficient to deduct any losses? If your S-Corp had a loss this year, you can only deduct it on your personal return to the extent of your basis. If you’re not sure what your basis is, this is a question for your accountant before you assume you can take the deduction.
Everyone — Before December 31
Review your mileage log. If you’ve been driving for business and not tracking it consistently, reconstruct what you can from calendar entries, client records, and memory. An incomplete log is better than no log — but get it as accurate as possible before the year closes.
Confirm your quarterly payments are complete. Q4 2026 estimated tax is due January 15, 2027 — so you still have time after December 31 for that one. But Q1 through Q3 should already be done. If you missed any, the penalty is running.
Pull together your charitable contribution documentation. Cash donations over $250 require a written acknowledgment from the charity. Non-cash donations of more than $500 require additional IRS forms. Make sure you have what you need before year end — you can’t reconstruct this documentation in April.
What Not to Do
Don’t make major financial decisions purely for tax reasons. Buying equipment you don’t need, making charitable donations you can’t afford, or contributing to retirement accounts that strain your cash flow — the tax tail shouldn’t wag the business dog.
Don’t assume last year’s strategy applies this year. Income level, business structure, tax law changes, and life circumstances all affect what moves make sense. What worked in 2025 may not be the right answer in 2026.
Don’t wait until December 30 to have the planning conversation. Some moves require setup time — a new retirement plan needs to be established before year end to make contributions, for example. Give yourself enough lead time to actually execute on whatever you decide to do.
Notice the timing. Our year-end planning conversations with small business clients happen in October and November, not on December 31, because the moves that actually reduce a tax bill take time to execute. Starting the conversation now is how you make sure you have it.