In my municipality we have the option of making contractors get a "Professional License" which would fall under Business License. It would help keep track of contractor's state licenses and making sure they have renewed them. We usually make them submit a copy of their contractor's license with every permit but if they didn't want the hassle they could apply for a professional license annually with updated copies of their state license, business license, and photo ID. We haven't rolled this out yet but that is the idea behind it.