561621 — Security Systems Services (except Locksmiths)
Description
This U.S. industry comprises establishments primarily engaged in (1) selling security alarm systems, such as burglar and fire alarms, along with installation, repair, or monitoring services or (2) remote monitoring of electronic security alarm systems.
Overview Facts
| NAICS Code | 561621 |
|---|---|
| Industry Title | Security Systems Services (except Locksmiths) |
| SBA Size Standard | $25,000,000 |
| IRS PBA Code | 561600 (rolled-up match) |
| Sectors Hierarchy | Sector 56 → 561 → 5616 |
| Source / Verified | US Census 2022 NAICS Manual / 2026-06-28 |
Legacy SIC Concordance
Trace the historical mapping chain from the 1987 Standard Industrial Classification (SIC) to the modern 2022 NAICS code format.
- SIC 7382 - Security Systems Services (via SIC1987:7382→NAICS1997:561621→2002:561621→2007:561621→2012:561621→2017:561621→2022:561621)
Related Resources & Compliance Guides
Further regulatory reference links for NAICS code 561621:
- 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.
- 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.
Related Industries in 5616
Frequently Asked Questions (FAQ)
Is 561621 a valid 2022 NAICS code?
NAICS 561621 is 'Security Systems Services (except Locksmiths)', a 2022 U.S. national industry under Sector 56 (Administrative and Support and Waste Management and Remediation Services); the SBA small-business size standard is $25,000,000.
What is the SBA size standard for NAICS 561621?
The SBA small business size standard for NAICS 561621 is $25,000,000 (based on receipts).
What is the legacy SIC code mapping for 561621?
NAICS code 561621 maps to the legacy 1987 SIC codes: 7382 - Security Systems Services.