Professional, Scientific & Technical Services Industry Classification Codes (SIC & NAICS)
Professional, Scientific & Technical Services Codes
Updated: 2025
The Professional, Scientific & Technical Services sector includes establishments that specialize in knowledge-based activities requiring advanced expertise, training, and professional judgment. This sector covers legal services, accounting and tax practices, engineering and architectural firms, management consultants, research organizations, advertising agencies, design studios, and a wide range of technical service providers. Professional services classifications support labor market analysis, contract procurement, regulatory oversight, and benchmarking of specialized service capabilities. Accurate SIC and NAICS codes ensure consistent rollups for economic modeling, market research, and compliance reporting.
SIC Coverage: Selected professional and technical activities drawn primarily from
SIC 73 (Business Services) and SIC 87 (Engineering, Accounting, Research, Management &
Related Services), including 7311, 7313, 7319, 7322, 7323, 7331, 7334, 7335, 7336, 7338, 7352,
7353, 7359, 7389, 8711, 8712, 8713, 8721, 8731, 8732, 8733, 8742, and 8748.
NAICS Range: 54
SICCODE.com assigns industries to this sector based on their primary reliance on professional expertise, specialized training, and technical judgment. SIC codes are included when their core activities align with advisory services, engineering and design, research and development, accounting and finance, management consulting, or other knowledge-intensive business services that correspond to NAICS Sector 54.
SIC vs. NAICS Structure for Professional, Scientific & Technical Services
| SIC Structure | NAICS Structure |
| Professional and technical services are distributed across SIC 73 (Business Services), SIC 81 (Legal Services), SIC 87 (Engineering, Accounting, Research, Management & Related Services), and selected SIC 89 codes. | Consolidated under NAICS Sector 54 — Professional, Scientific & Technical Services — with detailed industries for legal, accounting, engineering, design, consulting, research, and advertising services. |
| Advertising, credit reporting, direct mail, commercial art, photography, and business consulting are primarily captured in 73xx Business Services codes. | NAICS 54 groups these activities into professional subsectors for advertising, market research, design services, management consulting, and specialized technical support. |
| Engineering, architectural, surveying, accounting, and research services are found in the 87xx series, reflecting traditional professional practice lines. | NAICS 54 maintains distinct industries for engineering, architecture, surveying, accounting, scientific research, and management consulting, aligned with federal procurement and labor statistics. |
Major SIC Subsectors (Linked to Official 2-Digit Pages)
- SIC 73 — Business Services
- SIC 81 — Legal Services
- SIC 87 — Engineering, Accounting, Research, Management & Related Services
- SIC 89 — Miscellaneous Services (selected professional & technical activities)
Representative SIC Codes Within Professional Services (Linked)
- SIC 7311 — Advertising Agencies
- SIC 7313 — Radio, Television, and Publishers' Advertising Representatives
- SIC 7319 — Advertising, Not Elsewhere Classified
- SIC 7322 — Adjustment and Collection Services
- SIC 7323 — Credit Reporting Services
- SIC 7331 — Direct Mail Advertising Services
- SIC 7334 — Photocopying and Duplicating Services
- SIC 7335 — Commercial Photography
- SIC 7336 — Commercial Art and Graphic Design
- SIC 7338 — Secretarial and Stenographic Services
- SIC 7352 — Medical Equipment Rental and Leasing
- SIC 7353 — Heavy Construction Equipment Rental and Leasing
- SIC 7359 — Equipment Rental and Leasing, NEC
- SIC 7389 — Business Services, NEC
- SIC 8711 — Engineering Services
- SIC 8712 — Architectural Services
- SIC 8713 — Surveying Services
- SIC 8721 — Accounting, Auditing, and Bookkeeping Services
- SIC 8731 — Commercial Physical and Biological Research
- SIC 8732 — Commercial Economic, Sociological, and Educational Research
- SIC 8733 — Noncommercial Research Organizations
- SIC 8742 — Management Consulting Services
- SIC 8748 — Business Consulting Services, NEC
NAICS Structure Within Professional, Scientific & Technical Services (Linked)
In SIC, professional and technical services span multiple divisions, including Business Services (SIC 73), Legal Services (SIC 81), and Engineering, Accounting, Research, Management & Related Services (SIC 87). These codes reflect traditional professional practice lines such as law, accounting, engineering, architecture, research, and business consulting, as well as supporting services like advertising, credit reporting, commercial art, and equipment rental. NAICS consolidates this activity into Sector 54, providing a unified framework for professional, scientific, and technical services used in federal procurement, labor statistics, and economic analysis. Together, SIC and NAICS structures support comparison of legacy datasets with modern professional services markets.
Insights & Research for Professional Services
Classification data helps segment firms providing legal counsel, audit and assurance services, bookkeeping, tax preparation, and regulatory compliance advisory work.
SIC & NAICS codes group firms by engineering specialty, architectural practice, surveying, and other technical design and consulting capabilities tied to capital projects and infrastructure.
Consultants and research organizations use classification for market sizing, procurement eligibility, capability statements, and benchmarking across strategic advisory and research domains.
Professional service subsectors include advertising agencies, creative studios, commercial photographers, and technical specialists who support branding, marketing, and innovation programs.
How These Classifications Are Used
Professional, Scientific & Technical Services SIC and NAICS codes are used by procurement teams, regulators, contracting officers, professional firms, lenders, and researchers to categorize organizations by area of expertise. They underpin federal and state contracting categories, market research and competitive analysis, talent and workforce planning, peer benchmarks, and compliance frameworks. Accurate classification ensures that professional service firms are matched to the correct opportunity sets, reporting categories, and competitive groups in public and private sector procurement.
Get Help With Professional Services Classification
If you need assistance identifying the correct SIC or NAICS code for a professional, scientific, or technical services organization, our specialists can review service lines, capabilities, and regulatory definitions to confirm the proper classification for contracts, licensing, and reporting.
Related Classification Clusters
- NAICS 51 — Information (media, telecommunications, and digital platforms that intersect with professional content and data services)
- NAICS 56 — Administrative & Support Services (back-office, facilities, and support activities that complement professional service offerings)
Reviewed and verified by the SICCODE.com Expert Review Team.