There are 20 primary industries in the NAICS system (below). In the NAICS hierarchy, there are 96 subcategories (3 digit codes) and 317 industry groups (4 digit groups).
To properly determine your primary and possible secondary NAICS code you must work down the classification scheme until you find the best fit for your business. It is often the case that you determine that there is really no perfect fit when you get down to the four digit level.
For each two, three and four digit level there is an option, usually the last one shown, that says, “Not otherwise classified.” This is the choice to pick when you don’t fit close enough to a specific code.
|2 digit code||
|11||Agriculture, forestry, fishing and hunting|
|48–49||Transportation and Warehousing|
|52||Finance and Insurance|
|53||Real Estate and Rental and Leasing|
|54||Professional - Scientific and Technical Services|
|55||Management of Companies and Enterprises|
|56||Administrative and Support and Waste Management and
|62||Health Care and Social Assistance|
|71||Arts – Entertainment and Recreation|
|72||Accommodation and Food Services|
|81||Other Services (except Public Administration)|
|99||Industries Not Classified|
Every industry in the United States is assigned a North American Industry Classification System (NAICS) code. NAICS codes are used for a variety of purposes, from access to business loans to applying for federal contracts
A business may have a primary NAICS code (the code that best fits the business and describes its primary activities) and a secondary, or even third code (meaning the business also has characteristics of additional industries).
Many business databases will assign NAICS codes to articles and company profiles. Below is an example from Business Source Complete where a NAICS code is assigned to an article. Once you know the NAICS code for your company's industry, you can also search business databases by NAICS code.
There is a second older classification system known as Standard Industrial Classification (SIC) code that is still used but has been replaced, for most purposes, by the NAICS code.