How to Get an EIN in Wisconsin

How to Get an EIN in Wisconsin

How to Get an EIN in Wisconsin

An Employer Identification Number (EIN) is a federal tax ID that identifies your Wisconsin business to the IRS. If you're forming an LLC, corporation, partnership, or any business that will hire employees, collect sales tax, or open a business bank account, you'll almost certainly need one. The good news: getting an EIN is free, quick, and can be done online in minutes.

What Is an EIN and When Do You Need One in Wisconsin

An EIN is a nine-digit number issued by the Internal Revenue Service. It functions as your business's federal tax identification number, similar to a Social Security Number for individuals. The IRS uses it to track your business income, tax withholding, and employment records.

You need an EIN if your Wisconsin business falls into any of these categories:

  • You've formed an LLC with two or more owners (multi-member LLC)
  • You've incorporated as a C-corporation or S-corporation
  • You've formed a partnership of any kind
  • You plan to hire employees
  • You operate as a sole proprietor but want to open a business bank account under your business name
  • You're required to collect and remit Wisconsin sales tax
  • You file certain tax returns (excise tax, estate tax, trust tax)
  • You're an agricultural cooperative or corporation

If you're a sole proprietor with no employees and no separate business entity, you can use your Social Security Number instead. However, many sole proprietors get an EIN anyway for privacy and to keep business and personal finances separate.

Materials and Information You'll Need

Before you apply, gather the following:

  • Your Social Security Number (SSN) or Individual Taxpayer Identification Number (ITIN)
  • Your business legal name exactly as it appears on your state formation document (Articles of Organization, Articles of Incorporation, etc.)
  • Your business address in Wisconsin where you operate or maintain records
  • A mailing address where the IRS should send correspondence (can be the same as your business address)
  • Your business structure type (LLC, corporation, partnership, sole proprietor, etc.)
  • The date you started or expect to start your business
  • The type of business activity (e.g., consulting, retail, manufacturing)
  • Your Wisconsin Seller's Permit number (if you've already registered for sales tax with the Wisconsin Department of Revenue)

Note: You do NOT need to have already filed your Wisconsin LLC or corporation documents to apply for an EIN, though most business owners do this first.

How to Apply for an EIN in Wisconsin: Step by Step

Method 1: Online Application (Fastest)

The fastest way to get an EIN is through the IRS's online Form SS-4 application. You'll receive your number immediately upon approval, which typically takes a few minutes.

  1. Go to the IRS EIN online application. Visit the IRS website at www.irs.gov and navigate to the "Apply for an EIN" section. The official page is located under "Business Types" then "EIN (Employer Identification Number)."
  2. Select your entity type. On the application form, specify that you're applying from Wisconsin and select your business structure (LLC, corporation, partnership, sole proprietor, etc.).
  3. Enter your primary business activity code. The IRS uses North American Industry Classification System (NAICS) codes to categorize businesses. If you're unsure which code applies, search the NAICS database on the Census Bureau's website or describe your business and the form will guide you to the correct code.
  4. Provide responsible party information. You'll need to name the person responsible for the business (typically the owner or manager) and provide their SSN or ITIN, date of birth, and home address. This person does not have to be in Wisconsin.
  5. Enter your business location details. Provide your Wisconsin street address. P.O. Boxes are not accepted for the principal business location, so use your actual office, store, or workplace address.
  6. Confirm your mailing address. This is where the IRS will send your EIN confirmation letter. You can use your business address or a personal address.
  7. Review and submit. Double-check all information for accuracy. Misspelled names or incorrect addresses can delay use of your EIN.
  8. Receive your EIN immediately. Upon approval, the IRS displays your nine-digit EIN on screen. Write it down and save the confirmation page. You can use the EIN immediately for tax purposes.

Processing time: Same day (within minutes). No fee.

Method 2: Phone Application

If you prefer to speak with someone or have complex circumstances, you can apply by phone:

  1. Call the IRS EIN phone line. The number is 1-855-238-2869 (toll-free). Hours are 8 a.m. to 5 p.m. Eastern Time, Monday through Friday.
  2. Have your information ready. Before you call, gather the documents listed above. The phone agent will ask the same questions as the online form.
  3. Provide your details. Answer all questions thoroughly. The agent will assign an EIN and provide it verbally.
  4. Request the confirmation in writing. Ask the IRS agent to mail or email your EIN confirmation letter. You'll need this for your business records and to open a bank account.

Processing time: Same day (during the call). Confirmation letter arrives by mail within 2 to 4 weeks.

Method 3: Mail Application (Slowest)

If you cannot apply online or by phone, you can mail a completed Form SS-4 to the IRS:

  1. Download Form SS-4. Visit www.irs.gov and download "Application for an Employer Identification Number." The form is free.
  2. Complete all required fields. Fill out the form by hand (legibly) or type it. Leave no required field blank. If a field doesn't apply to your business, write "N/A."
  3. Determine the correct mailing address. The address depends on your state. For Wisconsin businesses, mail Form SS-4 to: Internal Revenue Service, EIN Operation, Cincinnati, OH 45-0818.
  4. Mail the completed form. Use regular first-class mail. Include your phone number so the IRS can contact you if they have questions.
  5. Wait for your EIN confirmation letter. The IRS typically processes mailed applications within 4 to 6 weeks. During this time, you cannot use your EIN.

Processing time: 4 to 6 weeks. No fee.

EIN for Sole Proprietors in Wisconsin

Sole proprietors can use their Social Security Number as their business tax ID. However, getting an EIN offers several advantages:

  • Separates your personal and business finances
  • Required if you hire employees (even one part-time worker)
  • Protects your personal information when dealing with vendors and customers
  • Allows you to open a business bank account in your business name

The application process is identical to applying as an LLC or corporation. Just select "Sole Proprietor" when asked about your business structure.

Wisconsin and Federal Tax Registration

Getting an EIN is only one part of registering your Wisconsin business for tax purposes. You'll also need to:

  • Register with the Wisconsin Department of Revenue for a Seller's Permit if you sell taxable products or services. Wisconsin's state sales tax is 5%, and businesses must collect and remit it. Registration is done through the Wisconsin Department of Revenue's Business Tax Registration system at tap.revenue.wi.gov/BTR/. The initial two-year permit costs $20, and renewals are $10 every two years.
  • File your Wisconsin business formation documents with the Wisconsin Department of Financial Institutions (for LLCs and corporations). Formation documents cost $130 for an LLC or $100 for a corporation if filed online.
  • Register with the IRS for payroll tax purposes if you'll have employees. You'll need your EIN to do this. The IRS will provide you with a Federal Employer Identification Number Account Number (FEIN) and instructions for paying payroll taxes.

For a centralized approach, use the Wisconsin One Stop Business Portal at onestop.wi.gov. This portal lets you register with the Wisconsin Department of Financial Institutions, the Department of Revenue, and the Department of Workforce Development in one application. It simplifies registration but still requires your EIN if you have multiple owners or employees.

Common Mistakes to Avoid

  • Using the wrong business name. Your EIN application must match the legal name on your Wisconsin state formation document exactly. Misspellings, missing words, or abbreviations create mismatches. If your LLC is called "Green Leaf Consulting LLC," don't apply as "Green Leaf LLC" or "Greenleaf Consulting."
  • Entering an incomplete or mail-only address. The IRS requires a physical street address for your principal business location. P.O. Boxes, mailbox rental services, and "care of" addresses are not accepted for this field. If you work from home, use your home street address.
  • Forgetting to note your EIN. If you receive your EIN verbally by phone or see it on screen during online application, write it down immediately. The confirmation letter takes weeks to arrive, and you may need the number before then to open a bank account or pay payroll taxes.
  • Applying before forming your entity (sometimes). While you can apply for an EIN before filing Articles of Organization, many banks and some systems require proof that your entity is actually registered with the state. File your Wisconsin LLC or corporation documents first, then apply for the EIN. This typically takes just one to two days longer and prevents headaches.
  • Applying for multiple EINs for the same business. Each EIN application creates a new IRS record. If you apply twice, you'll have two separate EINs. Use only one. If you accidentally receive two, contact the IRS to close the duplicate.
  • Providing an inactive responsible party. The "responsible party" listed on your EIN application should be someone directly involved in the business, not a lawyer or accountant hired just to file documents. This person should be reachable by the IRS if they have questions.

What to Do After You Receive Your EIN

Once you have your EIN, follow these steps:

  • Save your EIN confirmation letter. Keep the official letter from the IRS in a secure location. You'll need it when opening a business bank account, applying for loans, or during tax time.
  • Open a business bank account. Take your EIN confirmation letter, your Wisconsin business formation document (Articles of Organization or Articles of Incorporation), and a photo ID to your bank. This separates your personal and business finances and is critical for accounting and tax purposes.
  • Register with Wisconsin Department of Revenue if you haven't already. If your business sells taxable products or services, register for a Wisconsin Seller's Permit. You'll use your EIN on that application.
  • Set up payroll if you have employees. Use your EIN to enroll with the IRS for federal tax deposits and payroll reporting. The IRS provides instructions with your EIN confirmation letter.
  • Update your business documents. Include your EIN on invoices, contracts, and any official business correspondence. This ensures vendors, customers, and government agencies have the correct identifier for your business.

Is It Really Free

Yes. The IRS charges no fee for an EIN, regardless of which application method you use. If anyone asks you to pay for an EIN, they are scamming you. The only legitimate source for an EIN is the IRS. Beware of third-party EIN "services" that charge fees to apply on your behalf. You can do it yourself in minutes, at no cost.

Disclaimer and Professional Guidance

This article is informational and does not constitute legal, accounting, or tax advice. EIN requirements vary by business structure, ownership, and industry. The information provided reflects federal IRS requirements as of September 2026, but rules can change. Before applying for an EIN or making tax decisions for your Wisconsin business, consult with a qualified accountant or tax attorney who is familiar with your specific situation.

For additional guidance, contact the Wisconsin Small Business Development Center (wisconsinsbdc.org) or the U.S. Small Business Administration's Wisconsin District (sba.gov/district/wisconsin).

Next Steps for Your Wisconsin Business

Obtaining an EIN is one of the first steps in formalizing your business. After you have your EIN, you'll typically:

Getting your EIN early streamlines the rest of the business formation process and positions you to operate legally from day one.