NAICS to SIC Code

If you need to convert a NAICS code to its related SIC code, or the other way around, you are in the right place. Use the search tool above to enter either code and see exactly how the two systems connect.

What Is the NAICS to SIC Crosswalk?

The NAICS to SIC crosswalk is a reference table that shows how codes from the newer NAICS system relate to codes from the older SIC system. SIC stands for Standard Industrial Classification, and it was the primary business classification system used in the United States before NAICS replaced it in 1997.

Even though SIC is no longer the active standard, it has not disappeared completely. Some older government databases, legacy financial systems, and historical records still reference SIC codes, which is why a sic to naics mapping is still genuinely useful today. If you come across an SIC code on an old form, a Dun & Bradstreet listing, or a financial database, this crosswalk shows you the NAICS code it corresponds to under the current system, and the reverse works just as well.

Why You Might Need to Convert NAICS to SIC

There are a handful of real situations where this comes up. Some banks, insurance underwriters, and older databases still classify businesses by SIC code internally, even though they collect NAICS codes externally. If you are reviewing historical business or industry data, you will likely run into SIC codes that need to be matched against the current NAICS system to make sense of the numbers. Researchers comparing economic data across different time periods also rely on this crosswalk, since older statistics were recorded under SIC long before NAICS existed.

If you have ever searched for a sic code lookup and gotten confused by results that did not match what you expected from your NAICS classification, this is exactly the gap this page fills.

How to Use This NAICS to SIC Code Lookup

This tool works in both directions, so you do not need to know which system your code belongs to before you start.

To find a SIC code from a NAICS code, type your six-digit NAICS code into the search box. The tool will show you every related SIC code, since some NAICS codes map to more than one SIC classification depending on how broadly the old system grouped certain business activities.

To find a NAICS code from a SIC code, enter your four-digit SIC code instead. The tool will return the matching NAICS code or codes, along with the current 2022 industry title for each one.

If you only know the type of business you are researching and not a code number at all, you can also search by keyword. Type something like “liquor store” or “restaurant,” and the tool will surface both the NAICS and SIC matches together.

SIC to NAICS Mapping: It Goes Both Ways

It is worth understanding that this is not always a clean one-to-one relationship. Because NAICS was built with more detail and more industry categories than SIC ever had, a single old SIC code sometimes splits into several modern NAICS codes. The reverse also happens, where a few different NAICS codes all map back to the same broader SIC category. This crosswalk reflects those real relationships exactly as they exist in the official data, rather than forcing a simplified one-to-one match that would leave out useful detail.

This is also why a simple naics code list on its own is not always enough when you are working with older records. A list shows you the current codes, but a true crosswalk shows you how they connect to what came before.

Difference Between NAICS and SIC

NAICS and SIC were both built to do the same basic job, classify businesses by what they do, but they were designed decades apart and reflect very different economies. SIC was developed in the 1930s and last meaningfully updated in 1987, before sectors like modern technology, telecommunications, and many service industries existed in their current form. NAICS was introduced in 1997 specifically to address that gap, with a structure built in cooperation between the United States, Canada, and Mexico so that economic data could be compared consistently across all three countries.

NAICS also goes one digit deeper than SIC, using six digits instead of four, which allows for far more specific industry classification. That extra precision is part of why some older SIC codes split into multiple modern NAICS codes once you cross-reference them here.

Where to Find the Full NAICS Code List

If you already know you are working with a current NAICS code and just need to confirm or look it up directly, our main naics code list and search tool covers all 1,012 official 2022 codes with plain-English descriptions and real business examples for each one. This crosswalk page is built specifically for when SIC codes are part of the picture, whether that is an old record, a legacy system, or historical research.

Frequently Asked Questions

What is the NAICS to SIC crosswalk used for?

It shows how current NAICS codes relate to the older SIC codes they replaced, which is useful when working with legacy systems, historical data, or older business records that still reference SIC.

Is SIC still used today?

SIC is no longer the official classification standard in the United States, but some financial institutions, databases, and historical records still use it, which is why a working SIC code lookup remains relevant.

Can one NAICS code match more than one SIC code?

Yes. Because NAICS uses more detailed categories than SIC did, a single NAICS code sometimes relates to two or three different SIC classifications, and the crosswalk reflects each one.

Is this crosswalk based on the most recent NAICS edition?

Yes. This tool is built from the official 2022 NAICS to SIC crosswalk dataset, so every mapping reflects the current, active edition.

Do I need to know whether I have a NAICS or SIC code before searching?

No. You can enter either a NAICS code, a SIC code, or a plain business keyword, and the tool will identify the right matches automatically.