2022 NAICS national industry in sector 56 Administrative and Support and Waste Management and Remediation Services
561611 Investigation and Personal Background Check Services
NAICS 561611 is the US industry code for investigation and personal background check services. This U.S.
- Code
- 561611 (2022 NAICS)
- Title
- Investigation and Personal Background Check Services
- Part of
- Investigation, Guard, and Armored Car Services
- SBA small business limit
- Average annual receipts up to $25 million
- Closest UK SIC
- 80100, 80300 (details)
Changes coming. The NAICS 2027 revision applies to data from 1 January 2027, and SBA proposed new size standards on 20 August 2026. The values on this page are the ones in force today; we update this page when the official files change.
Official definition
This U.S. industry comprises establishments primarily engaged in providing investigation, detective, and personal background check services.
Examples Census gives
- Fingerprint services
- Private detective services
- Polygraph services
- Private investigative services (except credit)
When to use a different code
Census classifies these close-sounding activities somewhere else. Businesses mainly engaged in:
- Establishments primarily engaged in providing credit checks are classified in Industry 561450, Credit Bureaus.
Businesses that use this code
Activities listed under 561611
The Census index assigns these 12 activities to this code. If your business matches one, this is your code.
- Background check services
- Bounty hunting services
- Detective agencies
- Fingerprint services
- Investigation services (except credit), private
- Investigators, private
- Lie detection services
- Missing person tracing services
- Polygraph services
- Private detective services
- Private investigation services (except credit)
- Skip tracing services
SBA size standard for 561611
To count as a small business for SBA loans and federal contracts under NAICS 561611, your business (including affiliates) must not exceed $25 million in average annual receipts. Check your business.
Source: SBA table of size standards, effective March 17, 2023.
Closest UK SIC 2007 codes
There is no official one-to-one link between NAICS and UK SIC. These codes share the same international class (ISIC Rev. 4: 8010, 8030), so treat them as a starting point and check the definition.
Built from Census concordances 2022→2017 NAICS and 2017 NAICS→ISIC Rev. 4.
Similar codes to compare
Data last changed November 14, 2026. How this page is built.