# NAICS 561621: Security Systems Services (except Locksmiths)

Breadcrumb: [NAICS codes](https://bidrover.com/naics) › [561621 Security Systems Services (except Locksmiths)](https://bidrover.com/naics/561621)

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.

- NAICS code: 561621
- Title: Security Systems Services (except Locksmiths)
- Sector: 56 Administrative and Support and Waste Management and Remediation Services
- Subsector: 561 Administrative and Support Services
- Industry group: 5616 Investigation and Security Services
- NAICS industry: 56162 Security Systems Services
- SBA size standard: $25 million average annual receipts
- Open bids on BidRover: 2
- Updated: Oct 23, 2026

## Open bids (2)

- [Centennial Fire Alarm & CO Detection Upgrade and Maintenance Services](https://bidrover.com/bids/centennial-fire-alarm-and-co-detection-upgrade-and-maintenance-services--62b85ea3-7a43-4b3a-b62d-10c121eaf3e9) — Construction & facilities · Idaho, United States · due 2026-12-01
- [MI 2026-002 Fire Protection Services](https://bidrover.com/bids/mi-2026-002-fire-protection-services--0d5a4e21-20e0-461d-825b-53c4fa709d67) — Public safety & defense · Florida, United States · due 2026-10-23

## Frequently asked questions

### What is NAICS code 561621?

NAICS 561621 is "Security Systems Services (except Locksmiths)" in the 2022 North American Industry Classification System, in sector 56 (Administrative and Support and Waste Management and Remediation Services). 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.

### What is the SBA size standard for NAICS 561621?

A business is small under NAICS 561621 at or below $25 million average annual receipts, including affiliates (13 CFR 121.201). Confirm the standard named in each solicitation.

### How many government bids are open under NAICS 561621?

BidRover counts 2 open bids that cite NAICS 561621 as of Oct 23, 2026, refreshed every hour from official public sources. Many state and local notices do not list a NAICS code, so search by keyword too.

### How do I get alerts for NAICS 561621 bids?

Save an alert on this page. A free account gets new matching bids by weekly email; the Team plan ($19/mo) sends daily alerts with match scores, the buyer, source link and documents.

## Related NAICS codes

- [238210 Electrical Contractors and Other Wiring Installation Contractors](https://bidrover.com/naics/238210)
- [441330 Automotive Parts and Accessories Retailers](https://bidrover.com/naics/441330)
- [561622 Locksmiths](https://bidrover.com/naics/561622)
- [561611 Investigation and Personal Background Check Services](https://bidrover.com/naics/561611)
- [561612 Security Guards and Patrol Services](https://bidrover.com/naics/561612)
- [561613 Armored Car Services](https://bidrover.com/naics/561613)

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Code titles and definitions: U.S. Census Bureau, North American Industry Classification System (NAICS), 2022 (https://www.census.gov/naics/). Size standards: U.S. Small Business Administration, Small Business Size Standards, 13 CFR 121.201, eCFR text current as of 2026-10-21 (https://www.ecfr.gov/current/title-13/section-121.201).

BidRover lists bids from official public sources. It is not an issuing authority; confirm the NAICS code and size standard named in each solicitation.