Arizona

http://www.azroc.gov/l_class.html

Arizona has different licenses for residential and commercial work and has dual licensing to pay both on a single license. Residential construction is described as homes, townhomes, condos, cooperative units, and apartments with four units or fewer. A license is essential to bid on tasks of $750.00 or longer.

License search: http://www.azroc.gov/forms/contractorsearch.html