How to Register a Business in Wisconsin: Formation, EIN, and Tax Setup

To register a business in Wisconsin, you file formation documents with the Department of Financial Institutions, then layer on a federal tax ID, state tax registration, and any local or professional licenses your business needs. Most of the state filing can be done in one sitting through the One Stop Business Portal at onestop.wi.gov, which simultaneously registers you with the DFI, the Department of Revenue, and the Department of Workforce Development.¹ Online formation costs $130 for an LLC and $100 for a corporation.²

Step 1: Choose Your Business Structure

The structure you pick controls your liability exposure, your tax treatment, and how much paperwork the state expects from you. Wisconsin recognizes several forms:

A sole proprietorship needs no formation filing. You and the business are the same legal person, so personal assets are exposed to business debts. You can register a trade name with the DFI for $15 if you want to operate under a name other than your own.
A general partnership works the same way for two or more owners. No state filing is required, but a written partnership agreement is strongly recommended.
A limited liability company, governed by Chapter 183 of the Wisconsin Statutes, separates personal assets from business debts and lets one or more owners choose whether members or designated managers run the company.³
A corporation under Chapter 180 is a separate legal person with shareholders, directors, and officers. Record-keeping is stricter, but so is liability protection.⁴
A limited liability partnership is aimed at professional firms such as law or accounting practices. It’s formed by filing Form 602 (Statement of Qualification) with the DFI for $100.⁵

Most small business owners pick an LLC because it delivers liability protection without much formality. Corporations fit better when you plan to issue stock or bring in outside investors. A sole proprietorship is workable if you’re operating solo with low risk and understand that no liability shield exists.

Step 2: Pick and Verify Your Business Name

Your name has to be distinguishable from every entity already on file with the DFI. Search the Corporate Registration Information System (CRIS) online, or call the Corporation Bureau at 608-261-7577 for a verbal check. The DFI treats phone results as tentative because the pool of available names changes daily; a name isn’t actually yours until the department accepts your formation filing in writing.⁶

An LLC name must include “Limited Liability Company” or an abbreviation such as “LLC.” A corporation must include a designator such as “Inc.” or “Corporation.” An LLP must include “Limited Liability Partnership” or “LLP.”⁵

Step 3: Designate a Registered Agent

Every LLC and corporation in Wisconsin must maintain a registered agent and registered office in the state. The agent accepts legal documents on the business’s behalf: lawsuits, government notices, tax correspondence. Wisconsin Statute 183.0115 sets the rules for LLCs, and Section 180.0501 does the same for corporations.⁷

The agent must be a Wisconsin resident whose business office matches the registered office address, or a business entity authorized to operate in Wisconsin with an office at that same address. The registered office needs an actual street address, not a P.O. box or mail forwarding service, and the agent must keep an email address on file.⁷

You can be your own registered agent if you live in Wisconsin and use your home or office address. Owners who work from home often hire a commercial registered agent service instead to keep a personal address off public filings. That runs roughly $50 to $300 a year.

Step 4: File Your Formation Documents

With the name cleared and agent chosen, you can file.

LLC: Articles of Organization

LLCs file Form 502. You’ll list the company name, registered agent and office information, whether the LLC is member-managed or manager-managed, and the name and address of each organizer. The person who drafts the document must also be identified.⁸ Online filing costs $130; paper filing costs $170 and goes to the DFI office in Madison.²

Corporation: Articles of Incorporation

Corporations file Form 2. It requires the corporation’s name, the number and classes of authorized shares, registered agent details, and incorporator information. The fee is $100 whether you file online or by mail.²

Processing Times

Standard processing generally takes five to seven business days from the day the DFI receives your filing. If you need it sooner, pay an extra $25 and mark the filing “FOR EXPEDITED SERVICE.” Expedited filings are processed by the close of business the following business day.⁶

Step 5: Get a Federal EIN

Once the state confirms your formation, apply to the IRS for a federal Employer Identification Number. This nine-digit number is your business’s tax identity, and you’ll need it to file federal returns, open a bank account, and hire employees. The IRS specifically advises forming your entity with the state first, because applying before formation can delay your EIN.⁹

The online application at irs.gov is free and issues the EIN immediately. You’ll name a “responsible party,” meaning the individual who owns or controls the entity: the principal officer for a corporation, a general partner for a partnership. That person supplies a Social Security Number or ITIN.¹⁰

Any business with employees, and any corporation or partnership, needs an EIN. Single-member LLCs often get one anyway to keep personal and business finances separate.

Step 6: Register with the Wisconsin Department of Revenue

If your business sells taxable goods or services, or if you hire employees, you need a Business Tax Registration from the Department of Revenue. Form BTR-101 goes through the One Stop portal or directly to the department. The initial fee is $20 and covers two years; renewal is $10 every two years after that.¹¹

Registration assigns you a seller’s permit number authorizing you to collect and remit Wisconsin sales and use taxes. Every retail seller must have a seller’s permit for each location.¹² The department mails renewal notices, but a missed renewal is not a grace period for collecting sales tax without a valid permit. Set a two-year calendar reminder.

Step 7: Handle Employer Registrations If You Hire

Two obligations kick in almost immediately once you take on employees.

Workers’ Compensation

You must carry workers’ compensation insurance once you employ three or more workers (full-time or part-time counts), or once you pay $500 or more in gross wages during any calendar quarter for even one employee. The three-employee rule triggers coverage the day you hire the third person. The wage threshold triggers coverage by the tenth day of the first month of the next quarter.¹³

Unemployment Insurance

Commercial employers register for unemployment insurance with the Department of Workforce Development after paying $1,500 or more in wages in any calendar quarter, or after employing one or more people for any part of a day in 20 or more weeks during a calendar year. The weeks don’t need to be consecutive, and part-time employees count.¹⁴

The One Stop portal routes both registrations through DWD if you indicate on the formation flow that you’ll have employees.

Local Permits and Professional Licenses

State registration is not the whole story. Contact the clerk’s office in the city, village, or town where your business will physically operate. Common local requirements include zoning approval, signage permits, and general operating licenses, with fees and timelines that vary by municipality.

Before signing a lease on commercial space, confirm your intended use is allowed in that zoning district. Many municipalities require a certificate of occupancy before you open. When a special use permit is required, approval can stretch 45 to 60 days or longer. Opening without proper occupancy approval can trigger fines that are multiples of the normal permit fee.

Some professions require a separate credential from the Wisconsin Department of Safety and Professional Services. The DSPS regulates hundreds of occupations, from healthcare providers and accountants to barbers, real estate appraisers, and the construction trades. If your profession is on the DSPS list, you need the credential before offering services, and your general business registration doesn’t replace it.¹⁵

Adopt Internal Governing Documents

Formation puts you on the state’s books; it doesn’t say how the business runs internally. That’s the job of an operating agreement (for LLCs) or bylaws (for corporations).

Wisconsin law provides that an LLC’s operating agreement governs relations among members, the rights and duties of managers, and how the company conducts its activities.³ The LLC must keep a copy of every written operating agreement at its principal office.¹⁶ A useful agreement covers profit distribution, voting rights, exit procedures, and dispute resolution. Without one, the default rules in Chapter 183 apply, and those defaults rarely match what the owners actually intended.

Corporations should adopt bylaws covering board meetings, officer roles, shareholder voting, and dividends. Bylaws are not filed with the state; they’re internal.

Keep the Registration Alive

Registering the business isn’t a one-time event. Wisconsin requires an annual report from every LLC and corporation to keep the entity in good standing.

For a domestic LLC, the fee is $25 filed online, and paper filing adds a $15 surcharge. A domestic stock corporation pays $25 online or $40 by paper.² The report is due during the calendar quarter that contains your entity’s anniversary date, meaning the date the DFI originally accepted your formation filing. If you formed on May 15, the report is due by June 30 each year. If you formed on November 3, it’s due by December 31.¹⁷

Miss the report for several consecutive years and the DFI will administratively dissolve the entity. You’ll first appear on a Notice of Administrative Dissolution list, and if you still don’t file within 60 days, the department issues a Certificate of Administrative Dissolution. At that point the business loses its legal status, including the liability protection you formed it to get.¹⁸

One detail worth knowing before you ever need it: filing a final tax return with the IRS or the Wisconsin Department of Revenue does not close your entity with the DFI. Formally closing a Wisconsin business requires filing Articles of Dissolution directly with the department.¹⁸

1
State of Wisconsin. Wisconsin One Stop Business Portal
2
Wisconsin Department of Financial Institutions. DFI Corporation Fees
3
Wisconsin State Legislature. Wisconsin Statutes Chapter 183
4
Justia. 2025 Wisconsin Statutes Chapter 180 – Business Corporations
5
Wisconsin Department of Financial Institutions. Form 602 Mandatory Statement of Qualification Limited Liability Partnership
6
Wisconsin Department of Financial Institutions. Business Entity Frequently Asked Questions
7
Wisconsin State Legislature. Wisconsin Statutes 183.0115 – Registered Agent and Registered Office
8
Wisconsin Department of Financial Institutions. Form 502 – Articles of Organization
9
Internal Revenue Service. Get an Employer Identification Number
10
Internal Revenue Service. Instructions for Form SS-4 – Application for Employer Identification Number
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Wisconsin Department of Revenue. DOR Business Tax Registration
12
Cornell Law Institute. Wisconsin Admin Code Tax 11.002 – Registration
13
Department of Workforce Development. Worker’s Compensation Insurance Requirements in Wisconsin
14
Department of Workforce Development. Part 1 – Establishing Coverage, Section 2
15
State of Wisconsin Department of Safety and Professional Services. DSPS A-Z Professions List
16
Wisconsin State Legislature. Wisconsin Statutes 183.0110 – Applicability
17
Wisconsin Department of Financial Institutions. Annual Report Instructions – Nonstock Corporation and Limited Liability Company Annual Report
18
Wisconsin Department of Financial Institutions. Administrative Dissolutions