Pen, notebook and reading glasses on a wooden table, Sole Proprietorship in Wisconsin: How to Start One

Sole Proprietorship in Wisconsin: How to Start One

Last verified: November 10, 2026

Short answer to "can I apply for a sole proprietorship online?": there is nothing to apply for. The Wisconsin Small Business Development Center (SBDC) says state statutes do not require registration for a sole proprietorship, and the Department of Financial Institutions (DFI) files entities such as LLCs and corporations, not sole proprietors. If you sell or work under your own name and have not formed an entity, you are already a sole proprietor. What you can do online are the pieces around it: an optional DFI trade name, a Department of Revenue (DOR) seller's permit if you sell taxable goods or services, and an EIN.

This guide is for a solo owner with low liability exposure who wants the lightest legal setup and still wants to start cleanly. It is not for you if you will take on large debts or work where a mistake could cost a client real money; the LLC section below says why. If your question is only about a business name, read our guide to Wisconsin trade names and DBAs, which goes deeper on that one filing.

What a Wisconsin Sole Proprietorship Is, and Is Not

The IRS describes a sole proprietor as someone who owns an unincorporated business by themselves. In legal terms that means no entity stands between you and the business: a debt or lawsuit reaches your personal assets (the general rule for unincorporated owners; ask an attorney how it applies to your case). The business has no return of its own. Its profit is reported on your personal return, and Wisconsin taxes it at individual rates.

Under your own legal name, such as "Jane Kowalski Photography" for a photographer named Jane Kowalski, there is no name filing to consider at all. A name that does not include your own is a trade name, and Wisconsin's route for it is the DFI trademark program (Step 2).

What You Need Before You Start

  • A decision on whether you will work under your own legal name or a trade name
  • Your Social Security number; an EIN is free from the IRS and is required if you have employees
  • The $15 DFI filing fee, only if you choose to register a trade name
  • The $20 DOR registration fee for a seller's permit, only if you sell taxable products or services
  • A check with your city, village, town or county for local licenses, permits and zoning

Step-by-Step: How to Start a Sole Proprietorship in Wisconsin

  1. Step 1: Choose Your Business Name

    Decide between your own legal name and a trade name. Search the DFI business entity records for conflicts before you commit; DFI's FAQ says name availability can also reflect reserved names, and it directs questions to 608-261-7577. Searching is a screen, not clearance: nothing on the DFI side stops another business from using a similar name.

  2. Step 2: Register the Trade Name With DFI (Optional)

    DFI registers trade names through its trademark program under Wis. Stat. ch. 132, where a "mark" includes a trade name. The filing fee is $15, registration lasts 10 years, and renewal costs $15 and opens six months before expiry. DFI accepts these filings online or in person only, so there is no mail-in route. Registration is not required. It puts the name on a state record; it does not license you to operate and does not block a similar name. Fees are on the DFI trademark and trade name fee page.

    The SBDC adds that you may also register the name with your county Register of Deeds, which gives no protection beyond common law. We did not find a county fee in the sources we read, so ask your Register of Deeds what it accepts and charges.

  3. Step 3: Get an EIN if You Need One

    The EIN is free: IRS says "you never have to pay a fee for an EIN." The IRS page on who needs an EIN lists having employees as a reason. The pages we read do not say what a sole proprietor without employees must use, so ask the IRS or your tax preparer before you decide. Many owners get one anyway to keep their Social Security number off vendor forms; that is a choice, not a rule. Apply only at IRS.gov, never through a site that charges.

  4. Step 4: Register for a Seller's Permit With DOR

    Every seller of taxable products or services needs a seller's permit, according to DOR Publication 201, which says to apply at least three weeks before you open. The business tax registration fee is $20 and covers two years; renewal is $10 (DOR business tax registration FAQ). A sole proprietor registers directly with DOR through the Business Tax Registration portal.

    One Wisconsin quirk catches sole proprietors: the Wisconsin One Stop Business Portal, which files with DFI, DOR and the Department of Workforce Development (DWD) at once, supports only business corporations, statutory close corporations and LLCs. DOR's starting a business page lists sole proprietorships among those that register with DOR directly. Our seller's permit guide covers the permit in more detail.

  5. Step 5: Check Local Licenses and Zoning

    We looked for a general state business license in DFI's general information and FAQ pages, DOR's starting-a-business page, the One Stop Business Portal page, the DSPS credentialing FAQ and the SBDC FAQ, all read as archived copies from 2026. None describes one. That is not an official statement that none exists, so confirm with DFI or DOR. Regulated occupations are credentialed by profession through the Department of Safety and Professional Services (DSPS).

    Licensing in Wisconsin also happens locally, at the city, village, town or county. Ask the clerk where you will operate about licenses, health permits and zoning, especially for a home or storefront. See our home-based business guide, the city license pages and the Wisconsin business license overview.

  6. Step 6: Keep Business Money Separate

    A sole proprietorship has no legal line between you and the business, so a separate bank account is the only line you can draw yourself. That is our reasoning, not a Wisconsin rule; we did not look for a legal requirement either way. Ask your bank what documents it wants, such as a trade name record or an EIN letter.

  7. Step 7: Plan for Taxes

    Business profit goes on your personal Wisconsin return. For tax year 2026, the DOR Form 1-ES instructions show single filers taxed at 3.5% up to $15,110, 4.4% up to $51,950, 5.3% up to $332,720 and 7.65% above that; joint and separate schedules differ. Federal self-employment tax is figured on Schedule SE, per the IRS sole proprietorship page. Corporations, by contrast, pay Wisconsin's 7.9% franchise or income tax (DOR corporation tax FAQ).

    The state sales tax is 5%. Most counties add 0.5%, Milwaukee County 0.9%, and the City of Milwaukee 2% (DOR sales tax rates), so what you collect depends on where the sale is sourced. Ask DOR or a CPA whether you must make estimated payments.

Costs at a Glance

ItemCostNotes
State sole proprietorship filingNoneThe SBDC says statutes do not require registration
DFI trade name registration$15Optional; lasts 10 years; renewal $15
Seller's permit (DOR)$20 initial, covers two years; $10 renewalIf you sell taxable products or services
EIN (IRS)FreeRequired with employees
Local licenses and permitsVariesSet by your city, village, town or county

Common Mistakes

  • Assuming "no entity filing" means no paperwork. A seller's permit, a trade name and local licenses can still apply.
  • Using the One Stop portal as a sole proprietor. It is built for corporations and LLCs; register with DOR directly.
  • Treating a trade name record as protection. It is a state record, not clearance. Search before you spend on signs or a website.
  • Collecting no sales tax on taxable sales. Operating without a required permit can create back-tax exposure, so register before your first sale.
  • Staying a sole proprietor after the risk changes. See the next section.

Sole Proprietorship vs. LLC in Wisconsin

Our position: a sole proprietorship is a reasonable start for a solo, low-risk service or side business, and a poor fit once you sign leases, borrow money or work where an error could injure someone or cost a client heavily. An LLC separates you from the business, but it is not a guarantee, and a lender may still ask you to sign personally. This is reasoning, not legal advice; an attorney can say how it applies to you.

The LLC costs $130 for Articles of Organization filed online ($170 on paper), plus a $25 annual report filed online starting the year after formation (DFI fee schedule). Our Wisconsin LLC guide walks through it, and our comparison of filing it yourself with using a formation service covers the other route. For free, confidential advice on which structure fits, the Wisconsin SBDC offers no-cost consulting.

Frequently Asked Questions

Do I need to file anything with the state to become a sole proprietor in Wisconsin?

No. The SBDC says Wisconsin statutes do not require registration for a sole proprietorship. You may still choose a DFI trade name, and you need a DOR seller's permit if you sell taxable products or services.

How much does it cost to start a sole proprietorship in Wisconsin?

The state charges nothing for the sole proprietorship itself. The optional costs are $15 for a DFI trade name and $20 for a two-year seller's permit. Local licenses and professional licenses vary.

Can I hire employees as a sole proprietor in Wisconsin?

Yes. Get an EIN, then check two state thresholds. DWD's handbook says a commercial employer becomes covered for unemployment insurance with wages of $1,500 or more in a quarter, or employment in 20 or more weeks in a year (DWD employer handbook). Workers' compensation is required with three or more employees, or one or more paid $500 or more in a calendar quarter for Wisconsin work (DWD workers compensation for employers).

Is a sole proprietorship the same as an LLC?

No. An LLC is an entity filed with DFI; a sole proprietorship is not filed anywhere. The costs are in the LLC section above.

Sources

Disclaimer: This article is for general informational purposes only and does not constitute legal, tax, or accounting advice. Wisconsin business requirements can change, and your specific situation, industry, and local jurisdiction may involve additional rules not covered here. Consult a qualified attorney or CPA licensed in Wisconsin before making decisions about your business structure, tax elections, or licensing obligations.

Keep exploring: related Wisconsin guides