Most owners are buying tax preparation and assuming it is tax planning. They are different services, and the gap between them is usually worth $20,000 to $50,000 a year. Here is what the work actually involves.
Tax planning for business owners is the work of making decisions during the year that lower next April’s bill. Filing a return records what already happened. Planning changes what happens. For most owners the gap between the two runs $20,000 to $50,000 a year, and occasionally a great deal more.
I get some version of this call every February. Someone opens their draft return, sees a number they weren’t expecting, and asks what can be done about it. Usually the honest answer is: for that year, very little. The decisions that would have changed it were available in July and closed on December 31st.
That’s not a knock on anyone’s CPA. Most tax professionals are hired to file accurately and on time, and they do exactly that. Filing is a backward-looking job. Planning is a forward-looking one. They’re different services and most business owners are only buying the first one.
There are a handful of levers that do most of the work. The rest is rounding.
If you operate as a sole proprietor or a single-member LLC, every dollar of net profit is exposed to self-employment tax at 15.3% up to the Social Security wage base, then 2.9% above it. An S-corp election splits that profit into W-2 wages, which stay subject to payroll tax, and distributions, which don’t.
The catch is the word “reasonable.” Salary has to reflect what the work is actually worth. Pay yourself $30,000 on $300,000 of profit and you’ve built an audit case against yourself. Done properly, the savings are real and recurring — and the election has to be in place in time to count for the year you want it.
$12,000 a year
A contractor I met with had been operating as a sole proprietor for three years at a profit level where an S-corp election clearly made sense. The structure change reduced self-employment tax by roughly that much annually. He had been eligible the entire time. Nobody had raised it.
This is the largest deduction most owners have access to and the one most consistently underused. For 2026, total additions to one person’s 401(k) account are capped at $72,000, or $80,000 at age 50 and up. Your own salary deferral tops out at $24,500, so reaching the ceiling requires employer contributions — match and profit sharing — which is a function of how the plan is designed.
A plan built with a new comparability profit sharing formula can direct a disproportionate share toward older, higher-paid participants while still passing testing. In a lot of small businesses, that means the owner. There is a real cost for staff and I won’t pretend otherwise. The question is never whether you fund employees, it’s what ratio the math produces for your specific census.
Compare the plan types side by side →
Section 199A allows many pass-through owners to deduct up to 20% of qualified business income. Above certain income thresholds it starts phasing out, and for specified service businesses — consulting, health, law, financial services — it can disappear entirely.
What makes it a planning item rather than a filing item is that the inputs are partly under your control. W-2 wages paid by the business factor into the limitation. Taxable income determines the phase-out. Retirement contributions lower taxable income. Move one and the others move with it, which means the deduction can be planned for and frequently isn’t.
Income and deductions can often be pulled forward or pushed back a few weeks across a year-end boundary, and a few weeks is sometimes worth a full bracket. Equipment purchases, bonus timing, invoicing at year end, prepaying deductible expenses. None of it is exotic. All of it requires knowing roughly where you’ll land before the year closes, which means running a projection in the fall rather than finding out in March.
The years worth watching are the low ones — a heavy equipment year, a slow year, the gap after a sale and before Social Security and required distributions begin. Converting pre-tax dollars to Roth during a low-rate year costs the least it ever will, and it permanently reduces the RMDs that otherwise start at 73.
These windows are short and you have to see them coming. By the time the return is being prepared, the door closed on December 31.
| Mistake | What it costs |
|---|---|
| Staying a sole proprietor past the point it makes sense | Self-employment tax on profit that could have been distribution |
| Setting owner salary by guess | Too low invites scrutiny; too high wastes payroll tax |
| A retirement plan that was right five years ago | Tens of thousands in unused deduction capacity |
| Waiting until filing season to think about taxes | Every timing lever is already gone |
| Advisors who never speak to each other | Decisions that are individually fine and collectively wrong |
| Holding everything in pre-tax retirement accounts | No liquidity now, a large tax bill at 73 |
A new safe harbor 401(k) generally has to be effective by October 1. Leaving a SIMPLE IRA usually requires employee notice by early November for a January 1 change. Roth conversions and most timing moves close on December 31. A Solo 401(k) has to exist by December 31 to defer for that year, though profit sharing can follow at filing. The practical consequence: this is fall work, not spring work.
Here is the setup I find in most successful businesses. A CPA files the return in March, accurately, looking backward. Somebody manages an investment account without knowing anything about the business. An attorney drafted documents six years ago and hasn’t been heard from since. The 401(k) came from the payroll provider. Nobody has looked at all of it at once, and the owner ends up as the messenger between professionals who’ve never met.
What that produces isn’t dramatic failure. It’s a steady leak. Income deferred into a year that turns out to be higher. A conversion window nobody was watching. A buy-sell agreement that no longer matches what the business is worth. Beneficiary designations still naming an ex-spouse, which override the will regardless of what the will says.
Coordination is the actual product. Tax planning that informs retirement contributions. Contributions sized against what the business needs for working capital. Investment decisions made with the tax consequence known in advance. And somebody who talks to your CPA directly.
Send me last year’s business and personal returns and your current retirement plan documents. I’ll go through them and tell you what I see — where there’s room, what I’d look at first, and whether it’s worth doing anything at all. Some people I tell that their setup is already fine. That’s a legitimate outcome and it costs you nothing to find out.
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Tax planning is the ongoing work of making decisions during the year that reduce the tax you owe, as opposed to tax preparation, which reports what already happened. For business owners it typically covers entity structure, owner compensation, retirement plan contributions, QBI deduction optimization, and the timing of income and deductions around year end.
It varies with income and how the business is structured, but the gap between reactive filing and proactive planning commonly runs $20,000 to $50,000 a year for a profitable small business. The largest single lever is usually the retirement plan, where total 2026 contributions per person can reach $72,000, followed by entity structure and owner compensation.
Mid-year at the latest. A new safe harbor 401(k) generally must be effective by October 1, terminating a SIMPLE IRA usually requires employee notice by early November, and Roth conversions and most timing decisions close on December 31. By the time a return is being prepared in the spring, nearly every lever for that year has expired.
Most business owners benefit from both, because they do different jobs. A CPA prepares and files accurately. A planning-focused advisor makes forward-looking decisions about entity structure, retirement funding, and timing, and coordinates those with investments and estate documents. Problems usually appear where the two are not talking to each other.
Remaining a sole proprietor past the income level where an S-corp election makes sense, setting owner salary without a defensible basis, running a retirement plan that fit the business years ago, and waiting until filing season to think about taxes at all. Each of these is common and each is fixable with planning.
An LLC is a legal structure, not a tax structure, so the tax treatment depends on the election. A single-member LLC taxed as a sole proprietorship pays self-employment tax on all net profit. Electing S-corp treatment splits profit into wages and distributions, and only the wages are subject to payroll tax. Whether that helps depends on profit level and the salary you can reasonably justify.