Check a contractor's Wisconsin credential
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The Wisconsin Department of Safety and Professional Services maintains a public credential search. Enter the business or individual name and confirm the credential is real, current and not subject to discipline.
Most residential construction and remodeling in Wisconsin requires a Dwelling Contractor Qualifier credential. Electrical, plumbing and HVAC work require their own separate licenses — a general contractor is not automatically licensed for those.
If the name they give you does not appear, or the credential is expired or suspended, walk away. Do not accept "it is under my partner's name" without checking that name too.