How to Select the Correct SIC Code for Your Business
Selecting the correct SIC code starts by identifying your company’s primary revenue-generating activity, then choosing the official 4-digit SIC code that most accurately represents that activity at the establishment level.
Selecting a SIC code is a straightforward process when approached correctly. The most important step is identifying the primary industry your company operates in— not the products you sell incidentally, but the activity that generates the greatest share of revenue at a specific location.
Basic Guide for Selecting the Correct SIC Code
Within each general industry category, SIC codes break down into progressively more specific industries. For many common businesses—such as medical offices, plumbing contractors, or car dealerships—there is an exact SIC code match.
For newer, hybrid, or less standardized industries (such as emerging technology, specialized manufacturing, or mixed services), an exact match may not exist. In these cases, select the SIC code that most closely aligns with your core activity. Many industries include an NEC (Not Elsewhere Classified) option intended specifically for these situations.
Important: NEC codes are not “catch-alls” for convenience. They should only be used when no existing SIC definition accurately describes your primary business activity.
Identify Your Industry
Begin by identifying your top-level industry division. The first two digits of a SIC code define the broad industry category.
Use the SIC Code Lookup / Directory to browse industries by hierarchy or keyword.
Once you select a 2-digit division, the directory will display the full hierarchy down to the official 4-digit SIC code level. Each level becomes progressively more specific, moving from left to right.
Key Rules for Selecting a SIC Code
Industry Function Comes First
A company must select a SIC code based on what it does, not what it sells incidentally.
Example: A manufacturer should never select a retail SIC code, even if the retail description seems like a closer keyword match.
Consulting ≠ Industry Operated
Service providers must classify themselves by the service performed, not the industry they support.
Example: A mining consultant selects a consulting SIC code, not a mining SIC code.
What Is a Primary SIC Code?
Every business establishment has one primary SIC code. This code represents the activity that generated the highest revenue at that location during the previous year.
For multi-location companies, each establishment may require a different primary SIC code if activities differ between sites.
General Top-Level SIC Code Categories
The links below represent the official top-level SIC divisions: