I have been working on changing how we license contractors who work in our city limits by adding Classification levels and requiring them to be ICC certified to hold certain licenses, and changing our license fees that is currently only $50.00 a year for all contractors. 

Does your city or municipality require general contractors to take the exam and was it difficult to implement?  How did the contractors react to the license fee and exam cost?  How often do the contractors have retake the exam or can they renew with CEU’s through ICC?  Is your license fee and registration fee in addition to the cost of the exam? Do you find more contractors not registering due to the classifications?  How does your city or municipality police or enforce this?  

Any help would be appreciated, I will have to bring this before my City Manager and council so I want to be prepared with answers.

In the state of California, "contractors" are required to have a State Contractors license, or they are considered a "handyman".  By definition a handyman cannot do work valued at more than $500.  So, thats when the owner-builder form is used.  We look up licenses at https://www.cslb.ca.gov/, which makes it very easy.  We just require contractors to get a city business license, and verify their contractors license.