The North American Industry Classification System (NAICS) is the standard used by federal statistical agencies in classifying business establishments for the purpose of collecting, analyzing, and publishing statistical data related to the U.S. business economy. The system is maintained by the United States Bureau of the Census. The codes are also used by the State Tax Department to identify the business sector of your business activity. These codes are requested on your Business Registration Application, and can be attained here:

North American Industry Classification System