Convert SIC to NAICS Code
Convert Standard Industrial Classification (SIC) codes to their NAICS equivalents. Free SIC to NAICS crosswalk tool powered by Veridion.
What is SIC? (Standard Industrial Classification)
The Standard Industrial Classification (SIC) system was established in the 1930s by the U.S. government to classify business establishments by their primary economic activity. It was the dominant classification system in the United States for over six decades, used by the SEC, IRS, OSHA, and virtually every federal agency. SIC codes are 4-digit numeric codes organized hierarchically: the first two digits identify the major industry group (e.g. 73 = Business Services), while the full four digits identify the specific industry (e.g. 7371 = Computer Services). Although NAICS officially replaced SIC in 1997, SIC codes remain deeply embedded in financial systems, insurance underwriting, SEC filings (EDGAR), D&B reports, and many state-level business registrations. This is why SIC-to-NAICS conversion remains one of the most common industry code crosswalk needs.
| Full Name | Standard Industrial Classification |
| Maintained By | U.S. Office of Management and Budget (OMB) |
| Current Revision | SIC 1987 (last revision) |
| Region | United States (legacy) |
| Code Format | 4-digit numeric (e.g. 7371) |
| Total Industries | ~1,004 4-digit industries |
SIC vs NAICS: Key Differences
SIC and NAICS differ fundamentally in structure, coverage, and classification philosophy. SIC was production-oriented and static, while NAICS is process-oriented and regularly updated to reflect modern economic activity.
| Attribute | SIC | NAICS |
|---|---|---|
| Year introduced | 1937 | 1997 |
| Last updated | 1987 | 2022 |
| Code structure | 4-digit | 2- to 6-digit |
| Number of industries | ~1,004 | ~1,012 (6-digit) |
| Classification basis | Production-oriented | Process-oriented |
| Covers services sector | Limited | Comprehensive |
| Technology industries | Minimal (pre-internet) | Detailed (IT, telecom, etc.) |
| Regular updates | No (frozen in 1987) | Every 5 years |
| International alignment | US only | US, Canada, Mexico |
Frequently Asked Questions: SIC to NAICS
What is a SIC code?
A SIC (Standard Industrial Classification) code is a 4-digit numeric code assigned to business establishments to classify their primary economic activity. SIC was created by the U.S. government in the 1930s and was the primary classification system until NAICS replaced it in 1997. SIC codes are still widely used in SEC filings, insurance underwriting, legacy databases, and government records.
How do I convert a SIC code to NAICS?
Enter your 4-digit SIC code in the converter above and click "Convert to NAICS". The tool will instantly show you the matching NAICS 2022 code(s) along with their official titles and all related crosswalk mappings (including NACE and ISIC equivalents).
Why was SIC replaced by NAICS?
SIC was last updated in 1987 and could not adequately classify the service economy, information technology, and other modern industries that emerged in the 1990s. NAICS was developed jointly by the US, Canada, and Mexico to provide a more detailed, consistent, and modern classification system. NAICS uses a process-oriented approach (how a product is made) rather than SIC's production-oriented approach (what is made).
Is there always a 1-to-1 mapping between SIC and NAICS?
No. Some SIC codes map to multiple NAICS codes because NAICS provides finer granularity (for example, SIC 7371 may map to several distinct NAICS codes covering different software services). Conversely, some SIC codes were combined in NAICS. Our tool shows all matching NAICS codes for a given SIC input.
Are SIC codes still used today?
Yes. Despite being officially replaced by NAICS in 1997, SIC codes are still used by the SEC (all public company filings use SIC), OSHA, many state business registrations, insurance underwriting platforms, and financial data providers like D&B and Bloomberg. This is why SIC-to-NAICS conversion remains essential.
Where can I find a company's SIC code?
You can find a company's SIC code through SEC EDGAR filings (for public companies), D&B business reports, state business registration databases, or by using trueNAICS's company search tool which provides both SIC and NAICS classifications.
How many SIC codes are there?
The SIC system contains approximately 1,004 four-digit industry codes, organized under 83 two-digit major groups and 10 divisions (A through J). The divisions range from Agriculture (A) to Public Administration (J).
What is the SIC code format?
SIC codes are 4-digit numeric codes. The first two digits represent the major group (e.g. 73 = Business Services), the first three digits represent the industry group (e.g. 737 = Computer and Data Processing Services), and all four digits identify the specific industry (e.g. 7371 = Computer Services).
Can one company have multiple SIC codes?
Yes. Businesses are classified by their primary activity (primary SIC code), but companies with diversified operations may have secondary SIC codes. SEC filings typically list one primary SIC code, while other databases like D&B may assign multiple codes.
What is the difference between SIC and NAICS for insurance?
Insurance underwriters historically used SIC codes to assess industry risk. Many legacy rating systems still rely on SIC, but the industry is gradually migrating to NAICS. The key difference is that NAICS provides much finer granularity for modern services and technology industries, enabling more precise risk assessment. Converting SIC to NAICS helps insurers apply current classification standards.
Is this SIC to NAICS crosswalk free?
Yes. trueNAICS provides free, unlimited SIC-to-NAICS code conversions. Our crosswalk database covers all SIC codes mapped to NAICS 2022, with no registration or API key required.
How accurate is the SIC to NAICS conversion?
Our crosswalk data is sourced from the official U.S. Census Bureau concordance tables. While the mappings are authoritative, some SIC codes have multiple NAICS equivalents or approximate matches due to structural differences between the two systems. We display all possible mappings so you can select the most appropriate one for your use case.