Tax Planning
Year-End Tax Checklist for Business Owners
Most year-end tax savings come from decisions made in November and December — not in April. This is the same 12-point checklist we run with clients before December 31, organized in the order an owner should think through them.
Start with a clean tax projection
Before changing anything, build a projection of taxable income for the year using year-to-date numbers and a forecast of the remaining weeks. Without a baseline, every move below becomes a guess.
If revenue is materially up over last year, also project next year. A deduction that saves 24% today and pushes income into a 32% bracket tomorrow is a bad trade.
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Fund retirement plans on the owner side
Solo 401(k), SEP, and defined benefit plans are the largest single levers most owner-operators have. Employee deferrals usually need to happen by December 31; employer contributions often have until the return due date.
If you don't have a plan and want one in place for this year, December is your deadline to adopt one in most cases.
Place equipment in service — don't just order it
Section 179 and bonus depreciation require the asset to be placed in service by year-end, not just purchased or invoiced. Bonus depreciation has been phasing down (60% in 2024, 40% in 2025), which changes how aggressive equipment timing should be.
Run accountable plan and S-corp true-ups
S-corp owners should review reasonable compensation, accountable plan reimbursements for home office, mileage, and cell phone, and clean up any shareholder loans before year-end.
These are the items most likely to appear on an exam, and they are far easier to document in December than to defend in audit.
Check estimated payments against safe harbor
If income is up, the prior-year safe harbor (100% of last year, or 110% over $150K AGI) protects you from penalties even if you still owe in April. Top up Q4 to hit safe harbor before January 15.
Bunch charitable giving and consider a DAF
If your itemized deductions sit just under the standard deduction, a donor-advised fund lets you bunch two or three years of giving into one year to itemize, then take the standard deduction in off years.
Talk to your advisor before December 15
Most high-impact moves — retirement plan adoption, large equipment buys, Roth conversions, defined benefit funding — need lead time. Calling on December 28 limits you to whatever your bookkeeping software can pull.
Frequently asked questions
Is it too late to do tax planning in December?
Most retirement plan setups, accountable plan reimbursements, equipment placed-in-service decisions, and charitable bunching strategies can still be executed in December. Defined benefit plan adoption and some entity elections need more lead time and are usually off the table after early December.
What's the difference between this checklist and what my CPA does?
A typical tax preparer compiles documents in February and files the return. A planning relationship runs through this checklist in Q4 — when you can still influence the result — and adjusts decisions before they become permanent.
Want to apply this to your situation?
Book a consultation with a Kuuni Partners advisor — Georgia-based, serving clients nationwide.
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