The North American Industry Classification System (NAICS) is a business classification standard used by the governments of the United States, Mexico, and Canada for collecting various statistical data related to the US business economy. NAICS categories are classified as a code system. Businesses are assigned a code ranging from two to six digits long, depending on how wide or narrow the particular business's industry is. Each additional digit corresponds to a narrower subsect of an industry: the first two digits of the NAICS code relate to the economic sector, the third to the subsector, the fourth to the industry group, the fifth to the NAICS industry, and the sixth to the national industry. Complete and valid codes are six digits long.
The NAICS was developed under the Office of Management and Budget (OMB) by the Economic Classification Policy Committee (ECPC [acting on behalf of OMB]), Statistics Canada, and the Instituto Nacional de Estadistica y Geografia (INEGI) as the new standard for use by government statistical agencies in business classification for statistical data purposes in relation to the US economy. It was adopted in 1997, replacing the Standard Industrial Classification (SIC) system, with the goal of creating standard industry definitions for Canada, Mexico, and the US to make statistics near equally comparable.
Statistics collected include information on inputs and outputs, productivity, performance, employment, unit labor costs, and more. NAICS is production-oriented; the system groups businesses into industry categories according to process similarities between the businesses. Although it was designed to collect data for statistical use, it is also used for administrative, regulatory, contracting, and taxation purposes, among others.
NAICS codes are not assigned by a main government agency, nor by the organizations the system was developed under. Instead, they are determined by various agencies using various methods. Although businesses are assigned a code by the Census Bureau, this does not represent its "official" code. Other agencies can still determine the business's NAICS code for themselves. There is no official or central registration log for code assignments.