Year-End Tax Planning for Fractional Executives: What to Do Before December 31

Most fractional executives find out what their tax bill looks like in March, when nothing can be done about it. The useful window is the next 90 days. Year-end tax planning for fractional executives is mostly about decisions that expire on December 31: how much salary to run through an S-corp, whether a retirement plan exists, which expenses land in this year, and whether your estimated payments are big enough to avoid a penalty. Your first full year of fractional income is also the year most likely to surprise you, because nobody withheld anything. A few hours in October can be worth five figures in April.

Why year-end tax planning matters more once you're fractional

As an employee, your tax planning was mostly done for you. Payroll withheld, your employer matched a 401(k), and your W-2 told the whole story. Once you're running a practice, every one of those jobs is yours, and the calendar matters. Some moves have to happen inside the tax year. Others can wait until you file, but only under specific conditions.

The other change is volatility. Fractional income is lumpy. A strong third quarter can push you into a higher bracket, past the point where certain deductions phase out, or into an underpayment penalty you didn't see coming. That's why the planning has to start with a real projection: what you've earned so far, what's invoiced and likely to be paid before December 31, and what's realistically coming in the next three months. If you haven't built that view yet, the guide to taxes for fractional executives covers the basics of 1099 income, self-employment tax, and quarterly estimates.

S-corp owners: true up your salary before December 31

If your practice is taxed as an S-corp, the most important year-end decision is your salary. The IRS requires a reasonable wage for the work you do, paid through payroll, before you take distributions. Salary carries payroll taxes. Distributions don't. Getting the split right is where the S-corp election pays for itself, and getting it wrong is how it becomes an audit problem.

The Social Security portion of payroll tax only applies up to a wage base, which the Social Security Administration set at $184,500 for 2026. Above that, only the Medicare portion applies. For a fractional CFO or COO billing well into six figures, the salary decision has real dollars attached, and it has to be run through payroll by year end. It can't be fixed retroactively in March.

Salary also drives your retirement contributions. S-corp owners can only make 401(k) contributions from W-2 wages, and the deferrals have to go through payroll in the same calendar year. If you set a low salary in January and never revisited it, now is the time. If you're still deciding whether an S-corp makes sense at all, the LLC vs S-corp breakdown walks through the break-even math.

Retirement contributions are the biggest lever you control

For most independent executives, a Solo 401(k) is the single largest deduction available. You can contribute as both employee and employer. The employee deferral limit for 2026 is $24,500, with catch-up contributions on top for those 50 and older, and the employer profit-sharing contribution stacks on that.

Timing depends on how your practice is set up. Sole proprietors and single-member LLCs got a break under SECURE 2.0: a new Solo 401(k) can now be established after year end, up to the tax filing deadline without extensions, and still receive first-year employee deferrals. That makes April a fallback, not a plan. S-corp owners don't get the same flexibility, since deferrals have to come out of payroll during the year.

The 2027 limits haven't been announced yet. The IRS usually publishes them in late October or November, and projections put the deferral limit around $25,000 to $25,500. For the trade-offs between a Solo 401(k) and a SEP-IRA, see the retirement and benefits guide for fractional executives.

Timing income and expenses around the year-end line

Most solo practices use cash accounting, which means income counts when you receive it and expenses count when you pay them. That gives you some room to move. If 2026 has been an unusually strong year and you expect 2027 to be lighter, paying deductible expenses before December 31 pulls the deduction into the higher-rate year. Invoicing a December retainer on January 2 instead of December 28 can push that income into the lower one, though it's worth weighing against your cash needs and your client's own year-end close.

Equipment purchases are more favorable than they've been in years. The One Big Beautiful Bill Act made 100% bonus depreciation permanent and raised the Section 179 expensing limit to $2.56 million for 2026. For a fractional practice, that mostly means a new laptop, monitor, or home office setup can be deducted in full this year. Buy what you actually need. A deduction is never worth more than the cash it costs.

The same law made the 20% qualified business income deduction permanent. If your income is near the phase-out range, timing decisions can change how much of that deduction you keep. The QBI deduction guide explains why consulting income runs into the specified service trade or business limits.

Check your estimated payments before January 15

The fourth-quarter estimated tax payment for 2026 is due January 15, 2027. Before you make it, check whether you're covered by a safe harbor. In general, you avoid the underpayment penalty if your total payments for the year equal at least 100% of last year's tax, or 110% if your prior-year adjusted gross income was above $150,000. Many first-year fractional executives fall into this trap. Their old W-2 withholding covered part of the year, then the fractional income arrived with nothing set aside.

If you're short, the January payment is your last chance to close the gap. One useful wrinkle: if you or a spouse still has W-2 income, increasing withholding in December counts as if it were paid evenly through the year, which can fix an earlier shortfall that a late estimated payment can't. Practices with clients in several states should also check whether nonresident filing or estimated payments are owed elsewhere. The multi-state tax guide covers how that works.

Set up 2027 before it starts

The best year-end planning also prepares for next year. Set your 2027 S-corp salary in December, based on the rates and client load you expect, not on what made sense last January. Open a separate tax savings account if you don't have one, and move a fixed percentage of every client payment into it. Put the four 2027 estimated payment dates on your calendar now. And book time with a CPA in November, not April, while there's still something they can change.

None of this is complicated, but all of it is easy to put off. The executives who treat their practice like a business, with a projection, a calendar, and a few December decisions made on purpose, keep noticeably more of what they bill. Planning taxes is part of the job now, the same way finding the next client is.

The other half of a healthy practice is a steady pipeline, and that starts with being easy to find when companies are planning their 2027 hires. Create your free profile on ExecRoster.