Standards
North American Industry Classification System (NAICS)
A hierarchical industry classification for establishments in North America.
- Kind
- Vocabularies
- Steward
- Statistical agencies of the United States, Canada, and Mexico
- Official source
- https://www.census.gov/naics/
What it describes
NAICS classifies establishments by their primary economic activity for statistical purposes. Its hierarchy supports analysis at broad sector and more detailed industry levels. U.S., Canadian, and Mexican versions share a common framework, while national detail can differ. An organization with several establishments can therefore appear in more than one industry category across its operations.
A NAICS code is not a legal-entity identifier, licence, or proof that every activity of a company fits one category. Classifications can change between revisions, and a company may self-report a code in some administrative contexts. Keep the reporting source, country, establishment scope, and revision year. Compare historical data using an explicit crosswalk rather than silently treating codes from different editions as identical.
Structure
Hierarchical numeric codes; the shared scheme is defined through five digits, with national detail at six digits.
Useful for
- Group establishments by primary activity.
- Compare industry datasets.
- Track changes between classification revisions.
Limits
- Not a company identifier.
- One company may have multiple activities.
- National six-digit detail can differ.
How it is used in practice
NAICS was developed by the statistical agencies of Canada, Mexico and the United States so that economic statistics from the three countries could be compared. It classifies establishments by their primary economic activity and is used in economic censuses, employment statistics and business registers. In the United States, many regulatory and programme rules, including some size standards and eligibility definitions, are written by reference to NAICS codes. It succeeded the Standard Industrial Classification and is revised on a fixed cycle, with the most recent revisions taking effect in 2017 and 2022.
Codes are hierarchical. Two digits give the sector, and each additional digit narrows the industry, up to six digits for the national detail. Statistics agencies publish concordances between successive editions and between NAICS and other schemes.
A worked example
A fictional analyst wants to count biotechnology employers in a region. Business registry data attaches a NAICS code to each establishment. The analyst chooses the codes that cover research and development in the life sciences and counts establishments.
A reviewer asks three questions. Which edition of NAICS was in force when each record was coded? Were the codes assigned by the statistical agency or self-reported to a licensing body? And do multi-site companies appear once or once per establishment? The analyst's answers go into the record: the edition per source, the assignment method, and the unit of counting. An establishment coded under an older edition is mapped through the published concordance, and the mapping is cited. A count of companies and a count of establishments are different results, and the report says which is given.
Evaluating a claim that rests on a NAICS code
Check who assigned the code and why. Statistical agencies assign codes to establishments from survey responses, tax records or registrations. Other organizations assign codes for their own purposes, and a company may pick the code that fits a programme's eligibility. A code from a directory is a claim by the directory, not a finding by the statistical authority.
Check the year. Revisions merge, split and move industries, so a code can change meaning or disappear across editions. Comparing counts across revisions without the concordance produces artefacts that look like growth or decline. For claims about what a company does, the code is weak evidence, since the primary activity of an establishment can differ from the business of the company as a whole.
Confusions to avoid
NAICS is not a product classification. It classifies producers by activity, and products are classified in other systems. A firm in a manufacturing industry may sell services and vice versa. Treat the code as a statement about where an establishment sits in the economy and not as a list of what it sells.
It is also not the same as NACE, though both descend from the same international framework, nor the same as the older SIC. Any correspondence among them is partial, and many-to-many in places. Where a record holds codes from several systems, store each with its scheme and edition, and keep any mapping as a separate statement with its method.
Questions a reviewer can ask
Which edition of NAICS does each code come from? Who assigned it: a statistical agency, a licensing body or the company? Does the unit counted refer to an establishment or an enterprise? Is a concordance needed to compare years, and where did it come from? Does the claim concern the primary activity or all activities? Is a self-reported code being treated as a statistical finding?
Maintenance and change
The statistical agencies revise NAICS together on a five-year cycle, and each revision comes with concordance tables between the old and new codes. Revisions can create new industries for emerging activities, such as a code for a service that did not exist at the last revision, and retire others. Programmes and regulations that cite NAICS codes by number must decide whether to follow the revision. A size standard or eligibility rule written against the 2012 codes may be applied to 2022 data only through a concordance, and the result depends on how the concordance treats splits. Record the edition of every code, and the edition the governing rule cites.
Related terms
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