Wisconsin EIN vs the 15-Digit Wisconsin Withholding Number

After your EIN in Wisconsin

Wisconsin's Business Tax Registration, online or on paper Form BTR-101, lets you check every Department of Revenue permit you need on one application: withholding tax, seller's permit, use tax certificate, consumer's use tax certificate and other business taxes. Unemployment insurance is registered separately with the Department of Workforce Development.

Wisconsin gives employers a 15-digit withholding tax number that looks like 036-0000000000-00. The Department of Revenue says it is different from your federal EIN and asks you to use it, not the EIN, on all state withholding reporting and correspondence. You keep it permanently unless you close the account.

A single-member LLC that is disregarded for income tax still counts as an employer for Wisconsin withholding, so it needs its own Wisconsin withholding tax number. Generally, if you have to get a new EIN, such as after changing entity type, you must also register for a new Wisconsin withholding tax number.

Also on the Wisconsin list

• Register with the Wisconsin Department of Revenue through its online Business Tax Registration application for a seller's permit, withholding registration or other permits the business needs. An LLC must provide its FEIN on the application, and permits issued under Business Tax Registration are renewed every two years.
• File the annual report with the Department of Financial Institutions every year, starting the year after formation, during the calendar quarter in which the LLC's formation anniversary falls.

Agency sites checked November 1, 2026 · All 50 states

What is different about Wisconsin

• Wisconsin forms LLCs at the Department of Financial Institutions rather than a Secretary of State, and the annual report is due by the last day of the calendar quarter that contains the formation anniversary. An LLC organized in February files by March 31 each year; one organized in August files by September 30.
• Wisconsin lets the owner of a single-member LLC that is disregarded for income tax report the LLC's sales on the owner's own sales tax return. The owner may instead apply for a seller's permit in the LLC's name so the LLC gets its own seller's permit number; on that route, each of the owner's disregarded LLCs with taxable sales applies separately.
• Wisconsin's Articles of Organization, Form 502, must give an email address for the registered agent and, when signed in Wisconsin, the name of the individual who drafted the document. The LLC may not name itself as its own registered agent.

Before you apply

The SS-4 must match the Wisconsin Department of Financial Institutions filing; its entity ID is a state index, not a tax ID.

Wisconsin EIN questions