SIC Code

A SIC code (Standard Industrial Classification) is a four-digit numerical code that categorizes businesses by their primary type of economic activity. Originally developed by the U.S. government in 1937 and officially replaced by the NAICS system in 1997, SIC codes persist throughout the insurance industry because many carriers, rating bureaus, and agency management systems were built around them and never fully transitioned. The SEC and OSHA continue to use SIC codes for their own classification purposes. Agents encounter SIC codes on ACORD forms, carrier portals, and underwriting guidelines daily.

Why SIC Codes Matter for Independent Agents

Despite being nearly three decades past their official retirement, SIC codes remain embedded in commercial insurance workflows. The ACORD 125 — the master commercial insurance application — includes a field for SIC code right next to the NAICS code field. Many carrier portals, particularly those built on older technology platforms, still use SIC codes as their primary business classification input. Some carriers accept both; a few still only accept SIC.

This creates a practical problem for agents: you need to know both systems. A client tells you they run a janitorial cleaning business. The NAICS code is 561720 (Janitorial Services). The SIC code is 7349 (Services to Buildings and Dwellings, Not Elsewhere Classified). These numbers do not map one-to-one because the systems have different structures and granularity. Getting the wrong code entered — or entering a NAICS code into a SIC field — can result in incorrect rating, appetite mismatches, or outright submission rejection.

The ACORD 125 asks for both codes for exactly this reason. When completing a submission, agents should verify both the NAICS and SIC codes for the applicant's business. The U.S. Department of Labor (OSHA) and the SEC both maintain SIC code lookup tools. Cross-referencing with the Census Bureau's NAICS-to-SIC concordance table helps catch mismatches before submission.

How SIC Codes Work

SIC codes follow a four-digit hierarchical structure that is simpler but less granular than the six-digit NAICS system:

• First two digits — Major industry group (e.g., 15 = Building Construction - General Contractors, 73 = Business Services, 58 = Eating and Drinking Places)
• Third digit — Industry group within the major group
• Fourth digit — Specific industry

There are approximately 1,004 four-digit SIC codes across 11 divisions (Agriculture through Public Administration, plus Nonclassifiable Establishments). Compare that to the approximately 1,012 six-digit NAICS codes in the 2022 revision — the newer system provides finer granularity, which is one reason the government replaced SIC in the first place.

Here are SIC-to-NAICS examples that commercial agents encounter frequently:

Where SIC codes still dominate in insurance. Several areas of the industry rely heavily on SIC codes:

• ISO (Insurance Services Office) — ISO's commercial lines rating programs, including the Business Owners Policy (BOP) program, use SIC-based classification systems. When a carrier rates a BOP through an ISO-based program, the SIC code drives the class assignment.
• D&B (Dun & Bradstreet) reports — Credit and business information reports pulled during underwriting display SIC codes as the primary classification. Underwriters use these to verify that the business described in the application matches the business on record.
• Legacy carrier systems — Carriers that built their underwriting platforms in the 1990s or early 2000s often hard-coded SIC-based logic. Even after front-end modernization, the back-end rating engine may still translate every NAICS code to a SIC code before processing.
• Workers' compensation crosswalks — Some state rating bureaus maintain SIC-to-class-code mapping tables that help underwriters assign the correct workers' comp classification when the application only provides a SIC or NAICS code.

Common agent mistakes with SIC codes. The most frequent error is selecting a SIC code that is too broad or too narrow for the actual business operation. SIC 1731 (Electrical Work) covers everything from residential rewiring to high-voltage industrial installations — two very different risk profiles. When a carrier's system uses the SIC code to drive initial pricing, an imprecise code can produce a quote that is either uncompetitively high or unrealistically low, both of which create problems at binding or audit.

Related Terms

• NAICS Code — The six-digit classification system that officially replaced SIC codes and is used by newer carrier platforms and government databases
• NCCI Class Code — Workers' compensation classification codes that are separate from both SIC and NAICS but often cross-referenced during underwriting
• Risk Classification — The overall process of categorizing commercial risks, which uses SIC codes, NAICS codes, and carrier-specific class systems as inputs