How to Find Your SIC and NAICS Codes

If you’ve ever applied or explored applying for a business loan, you may have come across a few acronyms that sound more technical than they really are: SIC and NAICS.

These codes might just seem like administrative jargon, but they play an important role in how lenders, government agencies, and potential partners categorize your company. You may not know what they are, but your company has these codes. Understanding what they are and how to locate them is a straightforward step that can help you move faster through the loan application process.

What Are SIC and NAICS Codes?

SIC and NAICS codes are classification systems used to identify the primary economic activity of your business.

• SIC (Standard Industrial Classification): This is the older system, established by the U.S. government in the 1930s. While it has been largely superseded for statistical purposes, many lenders and older databases still use it to categorize businesses.
• NAICS (North American Industry Classification System): Introduced in 1997, this is the modern standard used by federal agencies to collect and publish statistical data on the U.S. economy. It’s more precise and reflects today’s modern economy better than the older SIC system.

Lenders use these codes to assess industry risk, benchmark your business against competitors, and determine eligibility for certain types of financing or government contracts. 

How to Find Your NAICS Code

NAICS is the current federal standard, so it’s the code you’ll most often be asked for on loan applications. Here’s how to find it:

1. Visit the Official Census Bureau Website: The U.S. Census Bureau maintains the official, searchable database for all NAICS codes. Head over to census.gov/naics.
2. Use the Keyword Search: Enter a keyword that describes your primary business activity, such as “bakery,” “HVAC repair,” or “consulting”.
3. Refine Your Results: The search will provide a list of industry categories. Click through the levels—from the broad sector down to the specific industry—to find the 6-digit code that most accurately describes your main revenue-generating activity.
4. Confirm the Definition: Each code comes with a description of what it includes. Read these carefully to ensure you aren’t selecting a related, but incorrect, category.

You may also use the NAICS Association’s US Company Lookup Tool to search existing business records.

How to Find Your SIC Code

If you’re working with an older lender or filling out documentation that specifically requests an SIC code, you will typically need to use a cross-reference tool.

Several websites, including the NAICS Association, provide “SIC-to-NAICS crosswalks” that let you search by your known NAICS code or by keyword to find the corresponding 4-digit SIC code.Sometimes, your business’s industry classification is listed on your previous tax returns or business registration documents filed with your state, too. Either of these places can be a reliable source to verify your code.

Why the Right Code Matters

You might be tempted to choose the “closest” code if you can’t find a perfect match, but accuracy is important.

Lenders use these codes to determine your business’s risk profile. If your NAICS code is incorrect, it could lead to complications during the underwriting process, such as issues with industry-specific lending caps or eligibility requirements.

Moreover, says Cody Schuiteboer, President and CEO of Best Interest Financial, “The correct NAICS code determines if a business is eligible for a contract with the government or if a business meets the SBA small-business size standards. The incorrect code can lock a business from doing work it is eligible for.”

Tips to Best Leverage Your SIC and NAICS Codes

By taking a few minutes to look up these codes accurately, you show lenders that you are organized and prepared—qualities they value just as much as the financial data you provide. Once you’ve identified your primary NAICS and SIC codes, keep them on file. Using the same codes across your tax filings, loan applications, and business plans creates a consistent profile that simplifies background verification.

If your business model is unique or straddles two different industries, don’t just guess. Ask for help from a loan officer or accountant. They’re familiar with these classification systems and can help you select the most appropriate code.