The North American Industry Classification System or NAICS (pronounced "nakes") is a system for organizing data on industries and companies for standardized reporting. Implemented in 1997 for the United States and Canada and in 1998 for Mexico, the classification system replaces the U.S. Standard Industrial Classification (SIC) system, as well as the respective classification systems of the other two nations.

The system provides common industry definitions for Canada, Mexico, and the United States. It replaces the three countries' separate classification systems with essentially one uniform system, while allowing for nation-specific customization at the finest level of detail. This means at the broadest levels of the NAICS hierarchy the three countries share common industry codes, but at the most detailed level (represented by six-digit codes) each country may choose to recognize additional sub-industries that are of particular importance to their national economies...