Doug Zandstra CPA CFE EA

9040 Town Center

Lakewood Ranch, FL 34202

941 538 5630

616 970 3000

dougzandstra@gmail.com

Starting a Business: Legal Structure vs. Tax Structure

One of the most common calls I get is from someone who is about to leave a W-2 job to work as a 1099 contractor, or start a side business, and wants to know: “What do I need to set up?”

The confusion almost always comes from mixing together two separate decisions that are not related:

The legal question — what kind of structure helps protect you if something goes wrong?
The tax question — once you have that structure, how do you want the IRS to tax it?

They are related, but they are not the same decision, and you do not need to solve both on day one.

The Legal Question: What Protects You?

The simplest way to be in business is to just be in business. For federal income tax purposes, someone operating directly under their own name is generally treated as a sole proprietor. Customers pay you personally, you report the income and expenses on your personal tax return, and you pay tax on the profit.

That does not necessarily mean there are no filings at all. Depending on the work and the state or city involved, a sole proprietor may still need a business license, professional license, sales tax registration, assumed-name or DBA filing, local permit, or insurance before starting work.

The catch is liability. As a sole proprietor, there is no separate legal entity between you and the business. If something goes wrong in the business, your personal assets may be exposed.

That is where an LLC or corporation can help. Forming an LLC can create legal separation between the business and the owner, but it is not an absolute legal wall. The owner still needs to treat the business like a real separate business: separate bank account, clean records, signed contracts in the company name, proper insurance, and no commingling of personal and business funds.

An LLC also does not protect the owner from everything. Personal negligence, personal guarantees, unpaid payroll taxes, professional malpractice, commingling, undercapitalization, or failure to follow basic entity formalities can still create personal exposure.

Whether you need that protection depends on your work. Someone doing low-risk clerical or office work may have a different risk profile than someone who is on a roof, doing electrical or welding work, driving for business, handling client funds, or hiring employees or subcontractors. The legal structure decision is mainly a risk-management decision, not a tax shortcut.

Formation and Governance

Once you decide you want that legal wall, the next choice is which entity to form — and this decision is made entirely under state law, not federal law.

The Tax Question: Once You Have an Entity, How Is It Taxed?

Forming an LLC does not automatically change how the owner is taxed. An LLC is a legal structure under state law. Federal tax classification is a separate question.

By default, a domestic LLC with one owner is disregarded as separate from that owner for federal tax purposes, while a domestic LLC with two or more members is taxed as a partnership unless it elects otherwise.¹

For a small owner-operator, the two most common approaches are default taxation and S corporation taxation.

Option 1: Taxed as a Sole Proprietor or Default Single-Member LLC

If you operate directly as a sole proprietor, or through a single-member LLC that has not made a corporate or S corporation election, the business profit generally flows onto your personal tax return. The income and expenses are usually reported on Schedule C.

The major tax issue is self-employment tax. A W-2 employee pays Social Security and Medicare tax through payroll withholding. The employee share is 7.65%: 6.2% Social Security plus 1.45% Medicare. The employer pays a matching 7.65%.

When you are self-employed, there is no separate employer to split it with. Self-employment tax is generally 15.3%, made up of 12.4% Social Security tax and 2.9% Medicare tax, subject to the Social Security wage base and other Medicare rules.^2,3

So it is more accurate to say that most net profit is subject to self-employment tax, not necessarily every dollar forever. Social Security tax is capped at the wage base, while Medicare tax continues, and higher-income taxpayers can also owe an additional 0.9% Medicare tax above certain income thresholds.²

For example, if your business has $100,000 of Schedule C profit, before regular income tax, the self-employment tax is roughly $14,130, assuming no other wages and income below the Social Security wage base. That is in addition to regular federal income tax and any state or local income tax.

Option 2: Electing S Corporation Tax Treatment

Once an LLC or corporation qualifies and elects to be taxed as an S corporation, the business files its own federal business return, but income generally passes through to the owner rather than being taxed at the entity level like a C corporation.⁴

An S corporation election is made by filing Form 2553, and all shareholders must consent.^5,6 A domestic eligible entity that timely elects S corporation status is treated as having made the necessary corporate classification election as of the effective date of the S election, assuming it qualifies.¹

Timing matters. For a calendar-year business that wants S corporation treatment effective January 1, Form 2553 is generally due by March 15 of that year, or can be filed during the preceding tax year. Late-election relief may be available if the requirements are met, but it should not be the plan.^5,6

The payroll tax treatment is the main reason S corporation status can save tax. The profit itself is not treated as self-employment income in the same way Schedule C profit is. But there is an important guardrail: an S corporation owner who works in the business must be paid reasonable compensation through payroll.

That salary is subject to Social Security and Medicare tax, split between the employee side and employer side. Amounts paid beyond reasonable wages may be treated as S corporation distributions rather than self-employment income. But if the S corporation pays too little salary to an owner who is actively working in the business, the IRS can reclassify distributions as wages.^7,8,9

There is no fixed formula for reasonable compensation. It cannot be zero for an owner who materially works in the business, and it should reflect what the business would realistically pay someone else to do the same work. But there is no rule requiring 50% of revenue, 50% of profit, or 100% of profit.

A Simple Example

Assume the business produces $100,000 before owner wages and employer payroll tax, and the owner takes a $40,000 reasonable salary.

Scenario	Payroll / self-employment tax result	Simplified effect
Sole proprietor / default single-member LLC	Roughly $14,130 of self-employment tax on $100,000 of Schedule C profit, assuming no other wages and income below the Social Security wage base.	Most of the business profit is exposed to self-employment tax.
S corporation with $40,000 salary	Roughly $6,120 of combined employer/employee Social Security and Medicare tax on $40,000 of wages, before other payroll costs.	Remaining profit generally passes through without self-employment tax, but the S corporation must run payroll and file a separate return.

In this simplified example, the S corporation savings are roughly $8,000 before considering state taxes, unemployment taxes, payroll service costs, bookkeeping costs, tax preparation fees, and the effect of the employer payroll tax deduction.

That is the tradeoff: S corporation status can reduce self-employment tax, but it adds payroll, bookkeeping, filing deadlines, and compliance costs.

What the S-Corp Election Actually Costs You

The tax savings are not free. S corporation status adds real ongoing administration.

Compliance Cost

Cost / compliance item	Sole proprietorship	Single-member LLC taxed like a sole proprietorship	LLC or corporation taxed as an S corporation
Initial setup / formation	Usually $0–$300+ unless licenses, DBA, permits, or local registrations are needed	Often $100–$800+ depending on state filing fees, registered agent, legal help, and licenses	Often $500–$2,000+ depending on entity formation, EIN, S-corp election, payroll setup, professional help, and state filings
State annual registration / annual report	Usually $0–$100+, unless a DBA, local license, or industry filing applies	Often $25–$800+ per year, depending on the state	Often $25–$800+ per year, plus any state S-corp, franchise, or entity-level taxes
Outside payroll company	Usually $0 if there are no employees	Usually $0 if there are no employees	Often $480–$1,800 per year for a one-owner payroll setup, depending on provider, payroll frequency, and state filings
Payroll taxes / unemployment taxes	Usually none for the owner; applies if employees are hired	Usually none for the owner; applies if employees are hired	Applies once the owner is paid W-2 wages. May include Social Security, Medicare, federal unemployment, state unemployment, and other state payroll costs
Bookkeeping	DIY or simple bookkeeping: $0–$1,500+ per year	Usually $300–$2,500+ per year, depending on activity and whether books are clean	Often $1,200–$6,000+ per year, because payroll, wages, distributions, reimbursements, loans, and balance sheet items need to be tracked
Tax preparation	Often $300–$1,000+ for Schedule C with the personal return, depending on complexity	Often $300–$1,200+ if still reported on Schedule C; more if there are state filings or multiple businesses	A few hundred to a few thousand dollars for the separate business return, plus the owner’s personal return
Separate business tax return	No separate federal business return for a basic sole proprietor; usually Schedule C with Form 1040	No separate federal business return for a default single-member LLC; usually Schedule C with Form 1040	Yes. The S corporation files Form 1120-S and issues a Schedule K-1 to the owner
Business return deadline	Personal return deadline generally applies	Personal return deadline generally applies	March 15 for calendar-year S corporations — not April 15
Administrative complexity	Low	Low to moderate	Moderate to high
Best fit	Very small or low-risk side business	Owner wants legal separation but does not yet need S-corp complexity	Business has consistent profit high enough that payroll tax savings justify added cost and compliance

Bookkeeping / Banking

Sole Proprietor / Single-Member LLC	S Corporation
Business and personal funds can be intermingled. Bookkeeping is minimal — simply track business expenses. Minimal cost.	Highly recommended to maintain a separate checkbook and bookkeeping function. Bank fees, accounting software fees, and the time (or cost of a bookkeeper) to keep the books accurate and up to date.

Also, do not rely on the idea that there is a general “short form” S corporation return just because revenue is modest. Form 1120-S is still required. Some smaller S corporations may avoid completing certain balance sheet and book-tax reconciliation schedules only if they meet the Form 1120-S Schedule B, question 11 conditions, generally involving both total receipts and total assets under $250,000.^11,13

If the owner pays business expenses personally and wants the S corporation to reimburse them, the business should use an accountable plan. Properly substantiated reimbursements under an accountable plan are excluded from wages, while nonaccountable plan amounts are included in wages and subject to employment taxes.^14,15,16

Health insurance for a more-than-2% S corporation shareholder has special rules. In general, premiums must be paid or reimbursed by the S corporation and included on the shareholder-employee’s Form W-2 for the shareholder to claim the self-employed health insurance deduction, if otherwise eligible.¹⁷

Practical Steps Once You Decide to Move Forward

Decide whether liability protection is needed. A sole proprietorship may be enough for low-risk activity. An LLC or corporation may make sense when the work creates meaningful liability risk, involves employees or subcontractors, or requires clearer separation between business and personal activity.
Open a separate business bank account. This is strongly recommended for any business and essential for clean LLC or S corporation administration.
Track deductible expenses from the beginning. Ordinary and necessary business expenses reduce taxable profit. Tools, supplies, software, advertising, insurance, professional fees, and business mileage can all matter.
Keep mileage records. For 2026, the IRS business standard mileage rate is 72.5 cents per mile from January 1 through June 30, and 76 cents per mile from July 1 through December 31.^18,19
Get insurance in place before taking on risk. General liability insurance, professional liability insurance, commercial auto coverage, cyber coverage, tools coverage, and workers’ compensation may all be relevant depending on the business.
Revisit retirement planning once income is predictable. A self-employed person may have access to retirement plan options such as a SEP IRA, SIMPLE IRA, or solo 401(k), depending on the business, income level, employees, and contribution goals.
Plan for quarterly estimated taxes. For 2026, an individual generally must make estimated tax payments if they expect to owe at least $1,000 after withholding and refundable credits, and withholding/credits are expected to be less than the smaller of 90% of the 2026 tax or 100% of the 2025 tax.²⁰ For higher-income taxpayers, the prior-year safe harbor is generally 110% instead of 100% if 2025 AGI was more than $150,000, or more than $75,000 if married filing separately.^20,21 The regular installment dates are April 15, June 15, September 15, and January 15 of the following year.^20,21
Calendar the March 15, not April 15, business return deadline. If your business is taxed as an S corporation or partnership and uses a calendar year, the federal business return is generally due March 15. Do not wait until April to send books to your tax preparer; by then, the business return may already be late, and the personal return may be waiting on the Schedule K-1.¹⁰

One more practical point on tools and equipment: equipment with a useful life beyond the year may need to be depreciated rather than deducted immediately. Depreciation generally begins when property is first used in the business.^22,23 Some qualifying property purchased for use in the active business may be eligible for section 179 expensing, subject to limits.²⁴ Tools or equipment already owned personally before the business starts can sometimes be depreciated after being placed in service, but they are not automatically deductible at original cost.

Step-by-Step Timeline

Step	Action item	Timing / deadline	Notes
1	Decide whether liability protection is needed	Before starting higher-risk work	A sole proprietorship may be enough for low-risk work, but an LLC or corporation can help separate business activity from personal assets.
2	Form the LLC or corporation with the state	Before using the entity	State filing rules, fees, annual reports, and franchise taxes vary by state.
3	Get an EIN from the IRS	After entity formation	Needed for payroll, business banking, and tax filings.
4	Open a separate business bank account	Before receiving business income	Keeps business income, expenses, owner draws, and reimbursements clean.
5	Decide whether to elect S corporation tax treatment	Once profit justifies payroll and compliance costs	A single-member LLC is disregarded by default, and a multi-member LLC is taxed as a partnership by default unless it elects otherwise. Treas. Reg. §301.7701-3(b)(1)(i)–(ii)
6	File Form 2553 if electing S corporation status	Generally by March 15 for a calendar-year election effective January 1	An S election is made by filing Form 2553, and all shareholders must consent. IRC §1362(a)(1)–(2); Treas. Reg. §1.1362-6(a)(2)(i)
7	Set up owner payroll if taxed as an S corporation	Before taking owner wages	A working S corporation owner must receive reasonable compensation through payroll. S corporation payments to an officer/shareholder must be treated as wages to the extent they are reasonable compensation for services. Pub. 15
8	Track business income and expenses	Ongoing	Clean books reduce tax preparation cost and make S corporation compliance easier.
9	Make quarterly estimated tax payments if required	April 15, June 15, September 15, and January 15	Individuals generally make estimated payments if they expect to owe at least $1,000 and withholding/credits are not enough to meet the safe harbor. Form 1040-ES; IRC §6654(c)(1)–(2), §6654(d)(1)(B)
10	File the business return	March 15 for calendar-year S corporations and partnerships	Do not wait until April. The business return usually produces the Schedule K-1 needed for the owner’s personal return. Calendar-year partnerships file Form 1065 by March 15. Form 1065 instructions
11	File the owner’s personal return	Generally April 15	The owner reports wages, business pass-through income, deductions, credits, and estimated tax payments on the personal return.
12	Maintain state filings and payroll compliance	Ongoing	Annual reports, state tax filings, payroll returns, workers’ compensation, and unemployment filings may apply.

Bottom Line

The legal structure decision and the tax structure decision are separate.

An LLC is mainly about legal separation and liability management. It does not automatically reduce taxes. A single-member LLC is generally taxed like the owner by default, while a multi-member LLC is generally taxed as a partnership by default unless it elects otherwise.¹

An S corporation election can reduce self-employment tax when business profit is high enough, but it comes with payroll, bookkeeping, separate tax filings, reasonable compensation requirements, and earlier deadlines.

For many new businesses, the better first step is to start simple, protect against real business risks, keep clean books, set aside money for taxes, and revisit S corporation status once profit is steady enough that the tax savings clearly outweigh the extra cost and complexity.

If you would like more specific information about the tax aspects of small business. What’s deductible, what’s not, well, I get those questions asked a lot as well, so I published a short book “Small Business Tax Essentials”. It’s available on Amazon https://www.amazon.com/Small-Business-Essentials-Doug-Zandstra-ebook/dp/B0BH1CMMK6

Are You Ready to Get Started ???

Ready to move forward?

Start your business formation intake here : https://www.cognitoforms.com/DougZandstraCPA/BusinessFormationInformation

begin your registrations.

For more information about S corporation operations, taxes, and small businesses, check out my book: Small Business Essentials, on Amazon.

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Steve Kitchen 941-500-5502

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aksala.com/team/steven-kitchen

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hannah.grill@adp.com

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Bryan Reeder 616-458-3994

Attorney

reedermurphy.com/contact

References

#	Citation	Link
1	§ 301.7701-3 — Classification of certain business entities	Link
2	IRC § 1401	Link
3	IRC § 1402	Link
4	Instructions for Form 2553, Election by a Small Business Corporation	Link
5	IRC § 1362	Link
6	§ 1.1362-6 — Elections and consents	Link
7	Court of Appeals Opinion	Link
8	Tax Court Decision	Link
9	Pub. 15 (Circular E), Employer’s Tax Guide	Link
10	Instructions for Form 1065, U.S. Return of Partnership Income	Link
11	Instructions for Form 1120-S, U.S. Income Tax Return for an S Corporation	Link
12	Instructions for Form 1120, U.S. Corporation Income Tax Return	Link
13	S Corporation Instructions for Schedules K-2 and K-3 (Form 1120-S)	Link
14	§ 1.62-2 — Reimbursements and other expense allowance arrangements	Link
15	§ 31.3401(a)-4 — Reimbursements and other expense allowance amounts	Link
16	§ 31.3121(a)-3 — Reimbursement and other expense allowance amounts	Link
17	Notice 2008-01	Link
18	Standard Mileage Rates — IRS.gov	Link
19	Internal Revenue Bulletin 2026-29	Link
20	Form 1040-ES, Estimated Tax for Individuals	Link
21	IRC § 6654	Link
22	IRC § 167	Link
23	Instructions for Schedule C (Form 1040)	Link
24	IRC § 179	Link