NAICS vs SIC codes: differences and crosswalk

SIC and NAICS are both ways to classify a business by industry. SIC, the Standard Industrial Classification, is the older four digit system, last revised in 1987. NAICS, the North American Industry Classification System, replaced it in 1997 with a six digit structure that is updated every five years. The SBA, the IRS, SAM.gov and nearly every lender now use NAICS. SIC survives mainly at the SEC and in older commercial databases.

Need your NAICS code? Describe the business in the NAICS code calculator and it returns the code.

What SIC was

Work on the SIC system began in 1937, when the federal government set up a committee to give its agencies one consistent way to classify industries. The first manual followed shortly after, and the system was revised several times, most recently in 1987. The 1987 edition is still the reference anyone means when they say "SIC code" today.

SIC codes are four digits. The first two digits are the major group and the next two narrow it down.

Why NAICS replaced it

By the 1990s SIC had fallen behind the economy. It had been built around manufacturing, and it had little room for services, technology and new industries. Software, cellular service and many health care activities were crowded into broad codes.

NAICS was built jointly by the United States, Canada and Mexico after the North American Free Trade Agreement, so the three countries could compare industry data. It made three big changes:

1. Production oriented. Businesses are grouped by how they produce goods or services, not by what they sell or who buys it.
2. More detail. Six digits allow far more industries, especially in services. NAICS 2022 has 1,012 United States national industries, according to the Census Bureau.
3. Regular updates. NAICS is revised every five years (2002, 2007, 2012, 2017, 2022), so it keeps up with new kinds of businesses. SIC has not been revised since 1987.

NAICS vs SIC at a glance

Where SIC still appears

SEC EDGAR. The SEC assigns a four digit SIC code to every company that files on EDGAR and uses it to route filings to review offices. That is why public company profiles show SIC rather than NAICS.

Commercial data providers. Dun and Bradstreet and other providers publish both SIC and NAICS codes, often an extended eight digit SIC of their own.

Some lenders and insurers. Older credit, pricing and policy systems were built on SIC and still store it. Most now map SIC to NAICS internally, and new applications ask for NAICS.

OSHA data. OSHA still publishes the SIC manual online and older inspection records use SIC.

SIC to NAICS crosswalk for common businesses

The Census Bureau publishes concordances from 1987 SIC to 1997 NAICS, and from each NAICS edition to the next. Many SIC codes split into several NAICS codes, so a crosswalk gives you candidates, not a final answer.

Notice how often one SIC code becomes two NAICS codes. SIC 5812 lumped every restaurant together, while NAICS separates table service from counter service, and lenders price those two differently.

How to convert SIC to NAICS

1. Find the SIC code's title and definition.
2. Look it up in the Census Bureau's 1987 SIC to 1997 NAICS concordance to get the candidate NAICS codes.
3. Carry each candidate forward to NAICS 2022. Codes changed in 2002, 2007, 2012, 2017 and 2022, and the 2022 retail and information changes moved many codes.
4. Read the NAICS 2022 definitions and pick the one that matches what the business actually does.

Or skip the chain: describe the business in the calculator and it goes straight to the NAICS 2022 code.

When the old SIC code is wrong for you today

Many businesses carry an SIC code that someone picked years ago and nobody revisited. Because SIC is so broad, the code may be technically right and still useless. SIC 7371, computer programming services, covers work that NAICS now splits between custom programming, systems design and software publishing. SIC 1521, general contractors for single family houses, covers both new home construction and remodeling, which NAICS separates into 236115 and 236118.

The safer approach is to ignore the old code, describe what the business does today, and choose the NAICS 2022 code that fits. Then use the new code everywhere you report one.

Which one a lender wants

Lenders want NAICS. Appetite lists, SBA eligibility checks, size standards and most underwriting models are written in NAICS codes. A few lenders still pull SIC from a credit report, and some insurance carriers still rate by SIC, but the application will ask for a NAICS code.

If your paperwork still shows only an SIC code, convert it and use the NAICS code from now on. Our guide on NAICS code lookup explains why databases sometimes disagree about which code a company has, and our page on NAICS codes and business loans explains how lenders use it. Start an application and the AI matches the deal to lenders that fund your code.