Single-Member LLC in South Dakota: Cost & Taxes (2026)

Fact-checked by the LegalGlass editorial team against primary sources · Published Aug 20, 2026 · Last updated Aug 20, 2026

A single-member LLC in South Dakota is formed with the same Articles of Organization as any LLC - $150 electronically - and is treated as a disregarded entity for federal income tax. Profit is reported on Schedule C and carries 15.3% self-employment tax.

Quick Answer

What it is: A one-owner South Dakota LLC - same Articles of Organization as any LLC
Formation fee: $150 electronic, $165 paper
Annual report: $55 electronic, $70 paper
Federal tax status: Disregarded entity by default (Schedule C)
EIN: Free; required with employees, excise tax, or a corporate election
Self-employment tax: 15.3% on net earnings; Schedule SE at $400+
Termination: Articles of Termination, $10
Registered agent: Required, physical South Dakota address

What a Single-Member LLC Is in South Dakota

A single-member LLC is an ordinary South Dakota limited liability company with exactly one owner. South Dakota does not have a separate statute or form for one-owner companies - you file the same Articles of Organization with the Secretary of State that a multi-member company files, and you get the same limited-liability protection.

The distinction that matters is federal. Under 26 CFR 301.7701-3, a domestic LLC with one member is a disregarded entity by default: the IRS ignores it for income tax and treats its activity as the owner's. State law and federal tax law disagree on purpose here, and that mismatch is the single most misunderstood feature of the structure.

Being disregarded for income tax does not mean the LLC is disregarded for liability. Properly formed and properly operated, a South Dakota single-member LLC stands between the business's creditors and the owner's personal assets exactly as a multi-member LLC does.

What It Costs to Form

The South Dakota Secretary of State's fee schedule sets the domestic LLC Articles of Organization fee at $150 filed electronically and $165 on paper - the paper price includes South Dakota's paper filing surcharge. Filing online is both cheaper and faster.

The recurring cost is the annual report: $55 electronically or $70 on paper. Closing the company later costs $10 for Articles of Termination. A federal EIN is free from the IRS, so anyone charging you for one is selling a service, not a government fee.

Filing	Electronic	Paper
Articles of Organization (create the LLC)	$150	$165
Annual report	$55	$70
Articles of Termination	$10	$10
Trademark or service mark registration	$125 (renewal $125)
Federal EIN	$0

How to Form One

Pick a distinguishable name with an LLC designator and confirm it through the South Dakota business entity search. Then appoint a registered agent with a physical South Dakota street address - see South Dakota registered agent requirements - and file the Articles of Organization electronically with the Secretary of State.

Immediately after acceptance, get a free EIN, adopt a written South Dakota operating agreement, and open a business bank account in the LLC's exact name. The full walkthrough is in how to form an LLC in South Dakota.

Does a Single-Member LLC Need an EIN?

Federally, a disregarded single-member LLC with no employees and no excise tax liability may use the owner's Social Security number for income tax. But the IRS requires an EIN once the LLC has employees, owes certain excise taxes, or elects corporate or S-corp treatment.

In practice you should get one anyway. It is free, it takes minutes, banks routinely require it to open a business account, and it keeps your Social Security number off W-9s you hand to clients. Apply on IRS Form SS-4 or through the IRS online application - never through a paid intermediary.

How a South Dakota Single-Member LLC Is Taxed

For federal income tax, the owner reports business profit on Schedule C attached to Form 1040 and computes self-employment tax on Schedule SE. The self-employment rate is 15.3% - 12.4% Social Security up to the annual wage base plus 2.9% Medicare with no cap - and Schedule SE is required once net earnings reach $400.

Because no employer withholds for you, the IRS expects quarterly estimated tax payments. Underpaying triggers penalties even if you settle up in April. Set aside a fixed share of every deposit rather than reconstructing the number at year end.

At the state level, South Dakota's Department of Revenue administers sales and use tax and contractor's excise tax rather than a personal income tax return on pass-through profit. If you sell taxable goods or services you will need a South Dakota sales tax license; see South Dakota LLC tax filing and self-employment tax in South Dakota.

When to Consider an S-Corp Election

A single-member LLC can file IRS Form 2553 to be taxed under Subchapter S. Doing so splits profit into W-2 wages, which carry employment tax, and residual distributions, which do not. The election is free and the deadline is two months and 15 days into the tax year.

The trade-off is real overhead: payroll registration, quarterly Forms 941, a W-2, a separate Form 1120-S, and a defensible reasonable-compensation figure. Below a few tens of thousands of dollars in profit the costs usually swamp the savings. See S-corp election in South Dakota and S-corp vs LLC.

Protecting the Liability Shield

Single-member LLCs draw more veil-piercing attention than multi-member ones, because there is no second owner to enforce formality. Courts look for commingled funds, missing records, undocumented owner draws, and a company that never behaved like a separate business.

The defenses are unglamorous and effective: a separate bank account, contracts signed in the LLC's name with your title, a written operating agreement even though nobody else signs it, records of member contributions and distributions, and a current annual report. Keeping the entity in good standing with the Secretary of State is part of the shield, not paperwork for its own sake.

Common Mistakes

Paying personal expenses from the business account is the most damaging habit and the easiest to avoid. Others include operating under a name different from the registered one without filing a South Dakota DBA, letting the registered agent lapse, forgetting the annual report, and assuming the LLC files its own income tax return when it is disregarded.

One more: assuming an LLC replaces insurance. It does not. A single-member LLC limits which assets a creditor can reach; it does not stop a claim from arising. Carry general liability or professional coverage appropriate to your work.

Frequently Asked Questions

How much does a single-member LLC cost in South Dakota?

The South Dakota Secretary of State charges $150 to file Articles of Organization electronically and $165 on paper. The annual report costs $55 electronically or $70 on paper. Articles of Termination cost $10. A federal EIN is free from the IRS. There is no separate fee for having only one member.

Is a single-member LLC disregarded in South Dakota?

For federal income tax, yes. Under 26 CFR 301.7701-3 a domestic LLC with one owner is a disregarded entity by default, so profit is reported on Schedule C of the owner's Form 1040. South Dakota state law still treats the LLC as a separate legal entity with its own liability shield.

Does a South Dakota single-member LLC need an EIN?

Not always for income tax - a disregarded LLC with no employees and no excise liability may use the owner's SSN. But an EIN is required once you hire employees, owe certain excise taxes, or elect corporate or S-corp treatment. It is free, so most owners get one to open a bank account and keep their SSN off W-9s.

Does a single-member LLC protect my personal assets?

Yes, if formed and operated properly. The LLC is a separate legal person, so business creditors generally reach business assets only. That protection weakens if you commingle funds, skip the operating agreement, sign contracts personally, or let the LLC fall out of good standing with the Secretary of State.

What taxes does a South Dakota single-member LLC pay?

Federally, the owner reports profit on Schedule C and pays self-employment tax at 15.3% on Schedule SE once net earnings reach $400, plus quarterly estimated tax. At the state level the Department of Revenue administers sales and use tax and contractor's excise tax rather than an income tax return on pass-through profit.

Do I need an operating agreement if I am the only member?

South Dakota does not require you to file one, but you should have one. It documents that the LLC is a distinct entity, sets out how contributions, distributions, and succession work, and is what banks and courts read. A single-member LLC without one looks more like a sole proprietorship to a judge.

Sources

South Dakota Secretary of State - Filing Fees (LLC Articles of Organization $150 electronic / $165 paper; annual report $55 / $70; Articles of Termination $10; trademark $125).
South Dakota Secretary of State - Limited Liability Companies (domestic LLC forms and filing options).
IRS - Single Member Limited Liability Companies (disregarded entity; when an EIN is required).
IRS - Limited Liability Company (LLC) (federal classification).
IRS - Get an Employer Identification Number (EIN is free).
IRS - About Form SS-4 (EIN application).
IRS - About Schedule C (Form 1040) (reporting a disregarded LLC).
IRS - About Schedule SE (Form 1040) (self-employment tax computation).
IRS - Self-Employment Tax (15.3% rate; $400 threshold).
IRS - Estimated Taxes (quarterly payment requirement).
IRS - About Form 2553 (S corporation election).
Legal Information Institute (Cornell) - 26 CFR 301.7701-3 (entity classification election).
Legal Information Institute (Cornell) - 26 U.S.C. 1402 (net earnings from self-employment).

LegalGlass provides general information for educational purposes and is not legal advice, is not a law firm, and is not a substitute for advice from a licensed attorney or tax professional. Laws, fees, and thresholds change; verify current amounts with the South Dakota Secretary of State and the South Dakota Department of Revenue before acting.