End of Year Tax Planning for Businesses: A Checklist Before December 31

Most tax savings disappear on December 31. After that, you’re filing a return, not making decisions. End of year tax planning for businesses works best when it starts now, while there’s still time to act on what you find. Here’s what to review before the year closes.

Income and Expense Timing Strategies

Whether to accelerate or defer income depends on where your tax bracket is headed next year.

If you expect similar or lower income next year, consider deferring December invoices into January and pulling planned 2027 purchases into this year. If you expect a stronger 2027, do the opposite: recognize income now while rates are favorable, and hold deductible spending until it offsets more next year.

This works cleanly for cash-basis businesses. Accrual-basis companies have less flexibility, since income is recognized when earned, not when paid.

Business Tax Deductions Companies Often Miss

A few categories get overlooked every year:

• Section 179 and bonus depreciation on equipment, vehicles, or software purchased and put into use before year-end.
• Retirement plan contributions — SEP-IRA, Solo 401(k), or 401(k) matches. Some can be funded up to the filing deadline but must be established before December 31.
• Bad debt write-offs for invoices you’ve genuinely given up on collecting.
• Prepaid expenses, like rent or insurance paid in December for next year, which may be deductible now under certain safe harbor rules.
• Charitable contributions made through the business, if that structure benefits you.

Not every deduction applies to every entity type, treat this as a starting list, not a blanket checklist.

Reconcile Your Books First

None of the above works if your books aren’t current. Reconcile bank and credit card accounts, clear miscategorized transactions, and confirm your profit and loss statement reflects reality before making any tax-timing decisions.

A plan built on inaccurate numbers isn’t a plan, it’s a guess with extra steps.

Revisit Your Business Entity Structure

If your business has grown, changed margins, or added owners this year, check whether your current entity structure (LLC, S-corp, C-corp) is still the most efficient. Entity elections have their own deadlines, and some changes only apply going forward. This isn’t a decision to make without an accounting team, but it’s one to raise before year-end, the lead time matters.

Estimate Your Tax Liability Before Year-End

Run a projection based on year-to-date numbers plus expected Q4 activity. This tells you three things: whether you’re under-withheld on estimated payments, what to plan cash flow around, and whether the moves above are worth the effort for your specific liability.

Guessing at this in April means you’ve lost the ability to act on what you find.

Key Takeaway

End-of-year tax planning for businesses isn’t about finding one clever move, it’s about closing the gap between what you could be doing and what your books currently show. Reconcile first, then work through timing, deductions, and structure in that order.