📆 Year-End Business Tax Planning

5 tax moves business owners should make before December 31 — and why waiting until January can cost you thousands

The short answer: Year-end tax planning for businesses isn't complicated — but it's time-sensitive. Several of the most valuable moves only work if you execute them before December 31. Prepaying expenses, timing income, purchasing equipment, setting up a retirement plan, and evaluating your entity structure can collectively save thousands. January is too late for most of these.

⚡ Must be executed before December 31 — some of these can't be done retroactively

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Move 1: Prepay business expenses before December 31

If you're on a cash-basis accounting method (which most small businesses are), you can deduct expenses in the year you pay them — not the year they relate to. That means paying January's rent, software subscriptions, or contractor invoices in December creates a deduction on your current-year tax return.

Romeo Razi, CPA — Year-End Tax Newsletter

"Pay January's expenses in December and write them off now. Even on a credit card — the IRS says it counts when you charge it, not on the date you pay the credit card balance. Think rent, software, contractors. But don't be cute — not a 3-year supply of logo hoodies."

The credit card rule is important and often overlooked: if you charge an expense to a business credit card in December, you get the deduction in the current tax year even if you don't pay the credit card until January. The payment is considered made on the date of the charge.

⚠ This only applies to legitimate business expenses you would incur anyway. Accelerating ordinary business expenses is fine. Prepaying for years of supplies you won't use is a gray area — the IRS can challenge prepaid expenses that don't have a clear business reason for the timing.

Move 2: Defer income to January (cash-basis businesses only)

If you haven't issued December invoices yet, consider waiting until January. Delaying when you invoice delays when you receive payment, which delays when you recognize the income for tax purposes.

Critical caveat: this only works if you're on the cash basis of accounting. If you're on the accrual basis, income is recognized when earned — not when cash is received. Holding a December invoice doesn't defer anything on an accrual basis.

Also critical: the payment actually has to arrive in January. A check that arrives December 31 is December income. A payment received January 2 is January income.

Move 3: Buy equipment before December 31 — and make sure it's in service

With 100% bonus depreciation now permanent (see our full guide at Bonus Depreciation 2025), any qualifying business equipment, software, or improvements purchased and placed in service by December 31 can be fully deducted this year.

Romeo Razi, CPA — Year-End Tax Newsletter

"New laptop? Espresso machine? $90K Ford F-250 for your 'construction biz'? Deduct it all this year, as long as you're using it and it's in service by December 31. If it's still in a box or not delivered by January 1st, no dice."

The in-service requirement is absolute. An asset ordered but not delivered by year-end doesn't qualify. An asset delivered but still boxed and uninstalled in your warehouse on December 31 doesn't qualify. It must be ready and available for use in your business.

Move 4: Start a retirement plan before year-end

Business retirement plans — SEP-IRA, SIMPLE IRA, and Solo 401(k) — offer much larger contribution limits than personal IRAs. Setting one up before year-end creates the opportunity to make deductible contributions that reduce your business income.

SEP
SEP-IRA
Up to 25% of compensation or ~$69,000 (2024). Simplest to set up. Can fund up to tax filing deadline including extensions.
Solo
Solo 401(k)
Up to ~$69,000 plus catch-up contributions if over 50. Must be established by December 31 (though contributions can be made later).
Credit
Startup Credit
Up to $5,000 dollar-for-dollar tax credit just for setting up a new retirement plan. Credit, not just a deduction — reduces your actual tax bill.

ⓘ The credit for setting up a new retirement plan is one of the most underused tax benefits for small businesses. If you've never had a retirement plan and you establish one this year, you could get a dollar-for-dollar credit of up to $5,000 on top of the deduction for contributions. This is a credit — meaning it reduces your tax bill by $5,000, not just your taxable income.

Move 5: Evaluate whether S-Corp status makes sense

If your business had a significantly profitable year and you're operating as an LLC taxed as a sole proprietorship or partnership, an S-Corp election can save substantial amounts in self-employment tax.

The mechanism: as an S-Corp owner-employee, you pay yourself a "reasonable salary" (subject to payroll taxes) and take the remaining profit as a distribution (not subject to self-employment tax). The savings can be thousands or tens of thousands annually for businesses with net income above roughly $50,000–$80,000.

Romeo Razi, CPA — Year-End Tax Newsletter

"Big year? It might be time to upgrade from LLC to S-Corp. S-Corps can save thousands in self-employment tax, but it's not for everyone, no matter what the TikTok gurus tell you. Good news: you can retroactively elect S-Corp status for the current year if you act soon."

⚠ The deadline to elect S-Corp status retroactively for the current tax year is typically March 15 of the following year (or the first day of the tax year for a new entity). However, the window to plan for it and ensure you're in compliance (payroll setup, reasonable compensation analysis) is before December 31. The S-Corp election is also not always the right move — additional compliance costs and complexity need to be weighed against the tax savings.

Frequently asked questions about year-end business tax planning

I'm on the accrual basis — can I still defer income by holding invoices?
Generally no. Accrual-basis taxpayers recognize income when it's earned and all events have occurred to fix the right to receive it — not when cash is received. Holding an invoice until January doesn't delay income recognition if the services were already performed. There are some specific timing rules for accrual-basis taxpayers, but they're more technical and limited.
How much does an S-Corp actually save in self-employment taxes?
Self-employment tax is 15.3% (12.4% Social Security + 2.9% Medicare) on net self-employment income. In an S-Corp, only your salary is subject to payroll taxes — not your distributions. If you're paying $180,000 out of an LLC, all $180,000 is subject to self-employment tax (~$25,000+ in SE tax). As an S-Corp with a $100,000 salary and $80,000 distribution, only the salary is taxed (~$15,000). Rough savings: $10,000+. The specific math depends on your situation.
Can I set up a Solo 401(k) right now if I'm a sole proprietor?
Yes — but the plan document must be signed and adopted by December 31 of the tax year you want to make contributions for. This is a common area where people miss the deadline: they intend to set up the plan but don't get the paperwork done by year-end. The contributions themselves can typically be made up to the filing deadline including extensions. But the establishment deadline is December 31 — don't miss it.
Romeo Razi, CPA
Former IRS Tax Examiner · CPA · Featured in MarketWatch, U.S. News & World Report
Romeo spent years inside the IRS as an auditor before founding Taxed Right LLC. He now helps taxpayers and business owners use the same insider knowledge to pay the least legally possible. Watch his IRS insider interview →

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