How to Establish a Sole Proprietorship in Wisconsin

Once you start a business, you automatically become a sole proprietor in Wisconsin. But you should still take steps to start your sole proprietorship, including choosing a business name, applying for licenses and permits, and obtaining an EIN.

By , Attorney Brigham Young University J. Reuben Clark Law School
Updated by David M. Steingold, Attorney
Updated 6/01/2023

If you've started selling your homemade jewelry online or running personal training sessions out of your garage, you've likely formed a sole proprietorship already—and you're not alone. When an individual starts a business (sells goods or services) and they haven't filed any legal documents with their state officially registering the business, then they've automatically created a sole proprietorship.

A sole proprietorship is low maintenance. It doesn't typically require you to file any creation documents or submit renewal filings or fees, and you can usually report your income on your personal tax return. But sole proprietors are personally liable for the business's debts and obligations, so you might need to dip into your personal funds to satisfy any debts your business can't pay.

In Wisconsin, you can establish a sole proprietorship without filing any legal documents with the Wisconsin state government. Though no action is required to legally create a sole proprietorship, you should follow four simple steps to start your business:

  1. Choose a business name.
  2. File a fictitious name with your county's register of deeds.
  3. Apply for licenses, permits, and zoning clearance.
  4. Obtain an employer identification number (EIN).

For more information, read our article on how to start a business in Wisconsin.

1. Choose a Business Name

As a sole proprietor in Wisconsin, you can use your own legal name or a fictitious name—also known as a firm name, "DBA" (for "doing business as"), assumed name, or, in some cases, a trade name. If you plan to use a fictitious name for your business, you should avoid using the same name as any other business currently registered with the state.

It's also a good idea to choose a name that's not too similar to another registered business to avoid trademark infringement. Under trademark law, your trade name can't be used by someone else in a way that would cause confusion among consumers. So, if you use a name that's the same as or too similar to someone else's trademark and you both provide similar goods or services, then you could be infringing on their trademark. If you find a competitor company already exists with a similar name, then it's best to choose another name.

For example, suppose you want to operate a food cart under the name Cheese Tops All Sandwiches. In the next town over, there's a restaurant called Cheeses All-Top Sandwich Shop that's been in business for years. Because your food cart would have a similar name to a restaurant that already exists, you should choose a different name.

To make sure your business name is available, you should run a search in the following government databases:

(For more information, read our FAQ on choosing and registering a business name.)

2. File a Fictitious Name With Your Register of Deeds

If you use a business name that's different from your legal name then, unlike many other states, it doesn't appear that Wisconsin requires you to register your business name. However, you might need to register a fictitious name—called a "firm name" if you want to apply for credit under a business name (Wis. Stat. § 134.17 (2023)). Check with your county or a local lawyer for further guidance.

Here's an example of how registering a fictitious name might work. Suppose Rudy Carroll provides basic bookkeeping services under the name Ever In Balance Books. Because Rudy's business name, Ever In Balance Books, isn't the same as his legal name, he might choose—or possibly even be required—to register his business name.

The Wisconsin Register of Deeds Association (WRDA) provides a downloadable copy of Registration of Firm Names form you can use to register your business name. The WRDA also provides a complete list of Wisconsin counties including contact information. As of 2023, the fee for recording a firm name is $30.

3. Apply for Licenses, Permits, and Zoning Clearance

Depending on your business activities, you could need to apply for business or professional licenses. By going to the starting a business section of the Department of Revenue (DOR) website, you can register your business with the DOR. You might also find help there regarding some forms of business licenses.

In addition, for more information on the licenses and permits you might need, check the:

Private sources worth checking for license questions include the Wisconsin Economic Development Corporation and the Wisconsin Technology Council.

You might also need to comply with local regulations, building permits, and zoning laws. Check with your city and county governments for more information. For example, the cities of Milwaukee and Madison each have webpages devoted to local licensing information. In addition, has a webpage that provides a Wisconsin county-by-county search of business licenses.

4. Obtain an EIN

Sole proprietors who wish to have employees need to obtain an EIN. This is a nine-digit number issued by the IRS for tax reporting purposes. All businesses with employees are required to report wages to the IRS using an EIN. You can register for an EIN online with the IRS.

Sole proprietors without employees aren't required to have an EIN. Instead, you can use your Social Security number to report taxes. Nevertheless, you might want to obtain an EIN. Some banks require an EIN to open a bank account, and having an EIN can reduce the risk of identity theft.

In Wisconsin, businesses are required to report taxes and file various employee reports with the DOR. You might need to use your EIN when reporting business taxes.

Next Steps for Sole Proprietors

You should consider taking the following steps once you've established your sole proprietorship:

  • Open a business bank account for your sole proprietorship. Using your business name and EIN, set up a bank account to keep your business and personal finances separate. You should keep your business income and expenses separate from your personal funds so you can easily distinguish your business's financial profile for tax purposes. For instance, you can more easily report business deductions on your tax return if you've created a separate account.
  • Obtain general liability insurance. Because sole proprietors are personally liable for all debts and obligations of the business, a business liability insurance policy can offer financial protection against unforeseen events. You should also consider other types of insurance for your business, including property and auto insurance. For more information, read our article on the types of insurance your small business might need.
  • Report and pay taxes. Depending on your specific business activities, you could be required to report such items as sales tax and use tax. You can get more information about sales and use taxes, employer withholding taxes, and other business taxes in the businesses section of the DOR website. (For more information, see our section on business taxes and deductions.)

To find out how to form a sole proprietorship in any other state, see our state guide to establishing a sole proprietorship.

Consulting a Small Business Attorney

You might not need to submit paperwork to start a sole proprietorship in Wisconsin. But your specific circumstances could require you to file certain forms and comply with certain rules and regulations. As a business owner, it's important to understand what steps you need to take to legally start and operate your sole proprietorship.

If you have business experience and only need to meet a few requirements to establish your sole proprietorship, you can probably do the work yourself. But if you need specific guidance or run into a complicated issue when starting your business, you should talk to a small business lawyer. A lawyer can help you register your name, file your taxes, and obtain licenses and permits.

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