SIC Lookup
The Standard Industrial Classification (SIC) system is a federal framework used to categorize businesses by the type of economic activity they perform. Originally developed in the 1930s and maintained by the U.S. government, SIC codes are still widely used today for regulatory filings, business licensing, credit applications, market research, and industry benchmarking.
Each four-digit code identifies a specific industry, nested within progressively broader groupings — from a single industry up through an industry group and into a major sector. Use the tool below to drill down through those levels and find the code that best describes your business’s primary activity.
SIC Lookup v3.0.0Last Update: May 11, 2026
Search the U.S. SIC industry classification. Enter at least 2 characters — results show the full Division › Major Group › Industry Group › Industry hierarchy. Search is case-insensitive and matches anywhere in the path or the code.
If you have worked in B2B marketing or sales, you have likely encountered a SIC code on a data form, prospecting list, or compliance filing. These four-digit numbers have been a fixture of American business for nearly a century. Despite being officially replaced by a newer system, they remain deeply embedded in the tools and workflows that sales teams rely on every day.
What SIC Codes Represent
The Standard Industrial Classification system organizes commercial and industrial activity into a hierarchy of four digits. The first two digits identify the major group, a broad sector such as Construction or Retail Trade. Adding a third digit narrows the focus to an industry group. The full four-digit code identifies a specific industry.
For example, a roofing contractor carries SIC code 1761. The first two digits (17) place it in the Special Trade Contractors category. The three-digit group (176) covers Roofing, Siding, and Sheet Metal Work. The fourth digit (1) pins it specifically to Roofing as a standalone industry. This specificity is why SIC codes became essential for targeting.
SIC Codes in B2B Marketing
Marketing teams primarily use these codes for list building and audience segmentation. Data providers index millions of businesses by SIC code, allowing a marketer selling commercial kitchen equipment to pull every food service establishment in a specific geography. Account-based marketing (ABM) programs also rely on these codes to build ideal customer profiles.
In digital advertising, many enrichment tools use these codes to classify company records before pushing segments to ad platforms. Furthermore, industry codes shape messaging strategy. A software company might serve both financial services (SIC 6020s) and healthcare providers (SIC 8000s). Mapping content to these defined verticals ensures the messaging resonates with the specific regulatory pressures of each audience.
SIC Codes in Sales Workflows
Sales leaders use these codes to size markets and define territories. By querying the count of establishments in a set of codes, a VP of Sales can estimate the total addressable market and set realistic quotas. Within a CRM, SIC codes serve as a normalizing field. This ensures that if different reps use different labels for an industry, the records remain categorized under a single, standard number.
In lead scoring, organizations often assign higher values to inbound leads that fall within their target SIC range. Additionally, in government contracting, these codes are often required fields on vendor registration forms and RFP responses.
The Limits of the SIC System
The SIC system was designed in the 1930s and last substantially revised in 1987. Consequently, the digital economy does not fit cleanly into a system built for an industrial era. Thousands of technology businesses are forced into catch-all codes that lump together wildly different business models. The system also struggles with conglomerates that operate across multiple industries but are assigned only one primary code.
The Transition to NAICS
In 1997, the North American Industry Classification System (NAICS) was introduced as the official replacement. This six-digit system allows for greater specificity and was designed to reflect the modern service and tech economy. NAICS created entirely new sectors for Information, Professional Services, and Management.
NAICS is now the standard for U.S. federal statistical agencies. Any market-sizing work that draws on government economic data should use NAICS codes for the most accurate picture. Most major data providers now provide both SIC and NAICS codes on company profiles.
Why SIC Persists
Despite the official transition, SIC codes remain common due to legacy systems. Many CRM platforms and internal databases were built around SIC and have not been fully migrated. Furthermore, the Securities and Exchange Commission still uses SIC codes for public company filings. There is also a level of professional familiarity; the four-digit system is often simpler to memorize and communicate than the six-digit NAICS equivalent.
Choosing the Right System
For modern B2B applications, the best approach is to maintain awareness of both. Use SIC when working with SEC filings, legacy CRM data, or specific regulatory contexts. Use NAICS when sizing markets with government data or when classifying companies in the technology, healthcare, and professional services sectors.
To optimize your data, audit your CRM to see if your customer codes align with your ideal customer profile. You can also use these codes to validate your market fit by identifying clusters among your highest-value accounts. Understanding both systems ensures better decisions regarding list building, segmentation, and data management.
