Wisconsin lesson 4 of 6
Get an EIN and register with the Department of Revenue
Your EIN identifies the LLC to the IRS and to your bank. A separate Business Tax Registration with the Wisconsin Department of Revenue is what lets you collect sales tax or withhold on employee wages.
Applying for the EIN
Apply for free directly on the IRS website once your Articles of Organization are approved. If the responsible party has a US social security number or ITIN, the EIN is issued immediately online; otherwise the application goes in on Form SS-4 by fax or mail, which takes longer.
Business Tax Registration
Separately from the EIN, an LLC that sells taxable goods or services, has employees, or owes certain other Wisconsin taxes completes Business Tax Registration with the Department of Revenue. This is where you obtain a seller's permit if you make taxable sales, and where you register for withholding tax if you hire staff.
Opening the account
Take your DFI confirmation, the EIN confirmation letter, an operating agreement if you have one, and identification for signers and significant owners. Run all business income and expenses through this account, since mixing personal and business funds undermines the liability separation an LLC is meant to provide.
Key takeaways
- The EIN is free and issued by the IRS.
- Business Tax Registration with the Department of Revenue is separate from the EIN and needed for sales or withholding tax.
- Keep business and personal funds in separate accounts.
Official sources
Or let us file your Wisconsin LLC for you
Everything above is yours to use for free. If you would rather hand it over, we prepare and file the Articles of Organization, act as your registered agent, and track your ongoing deadlines.
Last reviewed: September 2026 - reviewed by Gullia Filing Legal & Formation Team