According to Wisconsin state law, a plumbing license is required to install or replace plumbing, with few exceptions. So, before you get out your wrench, be sure to review the list below to determine if it is legally permissible for you to install your own plumbing. Homeowners may install plumbing without a license only under the following circumstances:

• The plumbing is located inside your home.
• The project to be completed is within a single-family residence.
• The home is the owner’s primary residence. A primary residence is defined as the address which the owner designates as his or her permanent residence for the purpose of voting or the address where the owner receives his or her state or federal tax mailings. (NOT a cabin, summer home, rental property or business.)
• The owner occupies the residence. (This means that under no circumstances may a homeowner without a plumbing license install plumbing related to new construction.)
• The plumbing is in a farm building on property owned and occupied by the owner. (EXCEPT where a license may be required by local ordinance.)
• In all cases check with your local municipality for permit and inspection requirements.

Also, you can check to see if the person or business you hire to install plumbing at your home or rental property possesses the proper licensing (link below) – beware of claims to install or replace plumbing by unlicensed individuals.

View related state laws in their entirety   HERE
Wisconsin DSPS “Plumbing License Laws" brochure  HERE
Check your Plumbers License Status at  DSPS  license search HERE