561611 — Investigation and Personal Background Check Services
Description
This U.S. industry comprises establishments primarily engaged in providing investigation, detective, and personal background check services (as defined in the official U.S. Census Bureau 2022 NAICS Manual).
Illustrative Examples
- Fingerprint services
- Private detective services
- Polygraph services
- Private investigative services (except credit)
Exclusions & Cross-References
- Establishments primarily engaged in providing credit checks are classified in Industry 561450, Credit Bureaus.
Overview Facts
Legacy SIC Concordance
Trace the historical mapping chain from the 1987 Standard Industrial Classification (SIC) to the modern 2022 NAICS code format.
- SIC 7381 - Detective, Guard, and Armored Car Services (via SIC1987:7381→NAICS1997:561611→2002:561611→2007:561611→2012:561611→2017:561611→2022:561611)
Suggested Product Service Codes (Advisory)
The following Product Service Codes (PSCs) are advisory suggestions aligned with this NAICS code. Note: NAICS and PSC codes map to different dimensions of procurement (industry vs. product/service). There is no official binding 1:1 crosswalk.
- PSC R430 — SUPPORT- PROFESSIONAL: PHYSICAL SECURITY AND BADGING
Source: DoD DPCAP PSC Selection Tool (Ingested: 2026-06-29)
Frequently Asked Questions (FAQ)
Is NAICS code 561611 valid in 2022? ▾
Yes, 561611 is a valid 6-digit 2022 NAICS national industry code representing 'Investigation and Personal Background Check Services' under Sector 56 in the official classification index.
What is the SBA size standard for NAICS code 561611? ▾
The Small Business Administration (SBA) has established a small business size standard of $25,000,000 for NAICS code 561611 (Investigation and Personal Background Check Services), calculated based on receipts.
What is the legacy SIC equivalent for NAICS 561611? ▾
According to official Census Bureau concordance tables, NAICS code 561611 (Investigation and Personal Background Check Services) maps to legacy 1987 Standard Industrial Classification (SIC) codes: 7381 - Detective, Guard, and Armored Car Services.
Related Pages & Tools
Further regulatory reference links for NAICS code 561611:
- Sector 56 Directory Hub — List of related industries in the Administrative and Support and Waste Management and Remediation Services sector.
- SIC ↔ NAICS Crosswalk Tool — Look up mappings between legacy SIC codes and modern classifications.
- NAICS 561611 to SIC Crosswalk — Bidirectional mapping to legacy SIC codes (Investigation and Personal Background Check Services).
- SBA Size Standards Guide — Complete rules and averaging periods for small business classifications.
- Calculating Annual Receipts Guide — Detailed worked example of revenue calculation rules.
- IRS Principal Business Activity Guide — How NAICS codes map to corporate and entity tax filings.