Senate Bill 403 aims to regulate online credit card contributions to political committees, conduits, and political parties in Wisconsin. The bill stipulates that no contributions made via credit card over the Internet can be accepted unless the contributor provides the credit card verification value or code, and the billing address associated with the card is located in the United States. An exception is made for U.S. citizens living abroad; if their billing address is outside the U.S., they must provide a mailing address in the U.S. that corresponds to their voter registration.

Additionally, the bill mandates that the treasurer of each political entity must keep records of the names and addresses of contributors for reporting purposes. It also imposes a penalty on financial institutions that process such contributions without adhering to the verification requirements, subjecting them to a forfeiture equal to the total amount of non-compliant contributions. This legislation seeks to enhance transparency and accountability in campaign finance by ensuring that contributions are properly verified.