You can find your SIC code by searching OSHA’s online SIC manual, which lets you look up codes by keyword or browse the full classification structure. Your SIC (Standard Industrial Classification) code is a four-digit number assigned to your business based on its primary activity, and several government agencies and business filings still require it.
What SIC Codes Are Used For
SIC codes were the original system the U.S. government created to categorize businesses by industry. Although the newer NAICS (North American Industry Classification System) has largely replaced SIC codes for federal statistics, SIC codes still show up regularly. The SEC requires them on corporate filings, insurance companies use them to assess risk, banks reference them during underwriting, and some state and local agencies still ask for them on registration forms or tax documents.
Each code is four digits. The first two digits identify the broad industry group (like “73” for business services), the third digit narrows it further, and the fourth digit specifies the exact activity. If you run a commercial printing shop, for example, your SIC code is 2752. A general medical practice falls under 8011.
Search OSHA’s SIC Code Lookup Tool
The fastest way to find your code is OSHA’s SIC System Search at osha.gov/data/sic-search. This tool is built on the 1987 SIC manual, which is the current and final version of the classification. You can use it three ways:
- Keyword search: Type a word that describes what your business does, like “landscaping,” “accounting,” or “restaurant.” The tool returns matching codes with descriptions so you can pick the best fit.
- Browse by division: If a keyword search gives too many results or nothing useful, you can browse the manual’s structure. It starts with broad divisions (Agriculture, Mining, Construction, Manufacturing, and so on) and drills down into increasingly specific categories.
- Look up a specific code: If you already have a two- or three-digit code and need the full four-digit version, you can enter what you have and see all the subcategories beneath it.
When you search, read the full description for each code rather than just matching on the title. Two codes can sound similar but cover different activities. A company that develops software, for instance, falls under a different code than one that sells packaged software off the shelf.
Check Your Existing Business Documents
If your business has been operating for a while, your SIC code may already be assigned and sitting in your records. Look at your previous tax filings, business insurance policies, SEC filings (if applicable), or any state registration paperwork. Banks and lenders also often record your SIC code when you open a business account or apply for a loan, so your original application paperwork may have it.
If you’ve filed with the SEC, your assigned SIC code appears on your EDGAR filings and in the SEC’s company search tool. The SEC assigns SIC codes based on the revenue breakdown you report, so if your business has multiple lines of work, the code reflects whichever activity generates the most revenue.
How to Pick the Right Code
Your SIC code should reflect your primary business activity, meaning the one that accounts for the largest share of your revenue. If you own a restaurant that also does catering, your primary code would be the one for eating places (5812), not the one for catering. You can sometimes list a secondary SIC code on certain filings, but the primary code is what matters most.
If your business spans two very different industries, look at where most of your money comes from. A company that manufactures furniture and also runs a retail showroom would typically use the manufacturing code if manufacturing drives most of its revenue.
Be as specific as possible. Using a broad two-digit code when a precise four-digit code exists can create problems. Insurance companies price policies partly based on SIC codes, so an overly broad code could mean you’re paying more than necessary or flagging your business inaccurately during a regulatory review.
Converting Between SIC and NAICS Codes
Some forms ask for a NAICS code instead of (or in addition to) a SIC code. NAICS is a six-digit system that replaced SIC for most federal data collection, and it categorizes industries differently. A single SIC code sometimes maps to multiple NAICS codes, or vice versa.
The U.S. Census Bureau publishes a free crosswalk table that maps every SIC code to its NAICS equivalent. You can find it on the Census Bureau’s NAICS page by searching for “SIC to NAICS concordance.” Enter your SIC code, and the table shows which NAICS code or codes correspond to it. This works in reverse too: if you know your NAICS code and need the SIC equivalent, the same concordance tables handle the conversion.
Keep in mind that the match is not always one-to-one. Some industries were reorganized when NAICS was created, so your SIC code might split across two or three NAICS categories. Read the descriptions for each option and choose the one that best fits your actual operations.