What's the NAICS code for security work?
It depends on the work. Security guards and patrol are 561612. Selling, installing and monitoring alarm systems is 561621. Installing cameras or alarms only, without selling or monitoring them, is 238210. Locksmiths are 561622.
The codes, side by side
| Code | What the Census index lists | Small business size limit | New federal contracts and orders, FY2026 | Of those, under $250,000 |
|---|---|---|---|---|
| 561612 Security Guards and Patrol Services | Security guard services | $29.0 million | 2,274 | 1,790 |
| 561621 Security Systems Services (except Locksmiths) | Security alarm systems sales combined with installation, repair, or monitoring services | $25.0 million | 1,226 | 1,038 |
| 238210 Electrical Contractors and Other Wiring Installation Contractors | Surveillance system, installation only; security and fire system, installation only | $19.0 million | 1,469 | 1,204 |
| 561622 Locksmiths | Locksmith services | $25.0 million | 54 | 52 |
Size limits are average annual revenue over the last five years, from the SBA table. Contract counts are from USAspending.gov, October 2025 to September 2026.
Guard services are the biggest of these in federal buying: 2,274 new contracts and orders under 561612 in FY2026, 1,790 of them under $250,000.
Other codes worth listing
- 561210 Facilities Support Services ($47.0 million): security as part of a whole-facility contract.
Agencies don't always code the same work the same way, so listing every code that fits gets more bids in front of you. Our guide to which NAICS codes to list explains how.
Common questions
What is the NAICS code for security guards?
561612, Security Guards and Patrol Services. Its size limit is $29.0 million in average annual revenue.
What NAICS code is security camera installation?
238210 if you only install the system. If you sell and install it, or monitor it afterward, it's 561621, Security Systems Services.
See the open bids under these codes
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Sources
- Census Bureau: 2022 NAICS index
- 13 CFR 121.201: SBA size standards
- USAspending.gov: contract awards, FY2026 (pulled Nov 2, 2026)
How we get our numbers: our sources and methods.