Company lists · Data refreshed September 2026

Top 25 Security companies for buildings based in the United States

RevenueBase identified 3,449 security companies for buildings headquartered in the United States as of September 2026 and tracks 209,766 professional contacts across them, including 22,437 with verified work emails and 64,122 with mobile numbers. New York is the largest hub.

This list covers security companies for buildings headquartered in the United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, how directly it supports the match, and when it was last checked. Data refreshed September 6, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row Match evidence on every row Refreshed Sep 6, 2026 86% judged on-target in blind review
3,449Companies
209,766Contacts tracked
22,437Verified emails
64,122Mobile numbers
Explore all 3,449 companies → Free signup · no credit card · 500 free credits

The 25 largest security companies for buildings based in the United States

Ranked by team size
Top 25 of 3,449 security companies for buildings based in the United States, ranked by team size, largest first. Data refreshed Sep 6, 2026. Evidence rates how directly each company's own description names security companies for buildings: strong (names it), partial (names part of it), indirect (matched on its full profile rather than the summary shown). Click a count to unlock that company's people.
#CompanyHeadquartersEmployeesContacts
1
Allied UniversalPartial evidence
Irvine, CA, United StatesHQ checked Sep 6, 202610001+62,804

“Allied Universal®, a leading security and facility services company, provides proactive security services and cutting-edge smart technology to deliver evolving, tailored solutions…”

Source: company website · checked Sep 6, 2026
2Parsippany, NJ, United StatesHQ checked Sep 6, 202610001+38,634

Securitas knows Security.”

Source: company website · checked Sep 6, 2026
3
UnemployedPartial evidence
St. Petersburg, FL, United StatesHQ checked Sep 6, 2026n/a4,038

“Excelsior Defense is a security and investigations company based out of St.”

Source: company website · checked Sep 6, 2026
4
Inter-Con SecurityPartial evidence
Pasadena, CA, United StatesHQ checked Sep 6, 202610001+3,612

“EVERYWHERE SECURITY MATTERS.”

Source: company website · checked Sep 6, 2026
5Roswell, GA, United StatesHQ checked Sep 6, 202610001+3,592

“U.S.”

Source: company website · checked Sep 6, 2026
6
Andy Frain ServicesPartial evidence
Aurora, IL, United StatesHQ checked Sep 6, 20265,001-10,0002,266

“Andy Frain Services.America's leading provider of integrated solutions to security and events needs for over 90 years.”

Source: company website · checked Sep 6, 2026
7
Walden SecurityPartial evidence
Chattanooga, TN, United StatesHQ checked Sep 6, 20265,001-10,0002,174

“Through an ISO® 9001:2015 Certified Quality Management System (QMS), Walden Security has earned an award-winning reputation for business excellence and employee satisfaction…”

Source: company website · checked Sep 6, 2026
8
EveronPartial evidence
Irving, TX, United StatesHQ checked Sep 6, 20261,001-5,0002,045

“Everon is a leading national provider of commercial security, video, fire, sprinkler, and life safety solutions for complex, multi-site businesses and organizations.”

Source: company website · checked Sep 6, 2026
9
Whelan SecurityIndirect evidence
St. Louis, MO, United StatesHQ checked Sep 6, 20265,001-10,0001,781

“Whelan’s commitment to quality and service has made us one of the foremost respected, successful and fastest growing companies in the industry.”

Source: company website · checked Sep 6, 2026
10
HSSIndirect evidence
Denver, CO, United StatesHQ checked Sep 6, 20265,001-10,0001,727

“HSS is now Tarian!”

Source: company website · checked Sep 6, 2026
11
Sunstates SecurityPartial evidence
Raleigh, NC, United StatesHQ checked Sep 6, 20265,001-10,0001,639

“Sunstates Security, LLC is one of the industry's leading providers of contract security services with a differentiated approach to providing successful, cost-effective, quality…”

Source: company website · checked Sep 6, 2026
12
Admiral Security ServicesPartial evidence
Bethesda, MD, United StatesHQ checked Sep 6, 20265,001-10,0001,441

“Admiral Security Services provides professional armed and unarmed uniformed security officers, unparalleled site management and unwavering corporate support that exceeds client…”

Source: company website · checked Sep 6, 2026
13Romeoville, IL, United StatesHQ checked Sep 6, 20261,001-5,0001,406

“As of May 2016, Protection 1 and ADT merged together to become the leading company in the electronic security industry.”

Source: company website · checked Sep 6, 2026
14New Orleans, LA, United StatesHQ checked Sep 6, 20261,001-5,0001,399

“Weiser Security Services is the 11th largest security service provider in the U.S.”

Source: company website · checked Sep 6, 2026
15
GuardsmarkPartial evidence
New York, NY, United StatesHQ checked Sep 6, 202610001+1,375

“Guardsmark, LLC provides security services.”

Source: company website · checked Sep 6, 2026
16North Kansas City, MO, United StatesHQ checked Sep 6, 20261,001-5,0001,276

“Established in Safe Haven Security has grown to become the nation’s largest ADT-authorized dealer, trusted by homeowners and businesses across the country.”

Source: company website · checked Sep 6, 2026
17
DSI Security ServicesPartial evidence
Dothan, AL, United StatesHQ checked Sep 6, 20261,001-5,0001,190

“DSI Security Services offers armed and unarmed uniformed security guard services.”

Source: company website · checked Sep 6, 2026
18
SOS Security LLCPartial evidence
Parsippany, NJ, United StatesHQ checked Sep 6, 202610001+1,151

“SOS Security is a known innovator and leader in the security and protective services industry.”

Source: company website · checked Sep 6, 2026
19
Titan Security GroupPartial evidence
Chicago, IL, United StatesHQ checked Sep 6, 20261,001-5,0001,138

“At Titan Security Group, we understand that each client is unique, with specific security needs shaped by the type of property and its location.”

Source: company website · checked Sep 6, 2026
20
PER MAR Security ServicesPartial evidence
Davenport, IA, United StatesHQ checked Sep 6, 20261,001-5,0001,120

“Per Mar Security Services is the largest full-service security solutions provider in the Midwest.”

Source: company website · checked Sep 6, 2026
21Pittsburgh, PA, United StatesHQ checked Sep 6, 20265,001-10,0001,062

“Founded in 1982, St.”

Source: company website · checked Sep 6, 2026
22
Planned CompaniesIndirect evidence
Parsippany, NJ, United StatesHQ checked Sep 6, 20261,001-5,0001,035

“Planned Companies, an innovative leader in the real estate service industry, is committed to providing the most accountable and professional service for its valued clientele.”

Source: company website · checked Sep 6, 2026
23
First Coast SecurityIndirect evidence
Jacksonville, FL, United StatesHQ checked Sep 6, 20265,001-10,000932

“As an established mid-market company, clients throughout the country entrust us as the best-qualified firm to protect their highest-value assets – while delivering the quality…”

Source: company website · checked Sep 6, 2026
24
Security 101Partial evidence
West Palm Beach, FL, United StatesHQ checked Sep 6, 2026501-1,000849

Security 101® is a nationwide leader in designing, installing, and maintaining advanced security systems tailored to the unique needs of organizations of all sizes.”

Source: company website · checked Sep 6, 2026
25Uniontown, OH, United StatesHQ checked Sep 6, 202610001+839

Securitas knows Security.”

Source: company website · checked Sep 6, 2026

Showing 25 of 3,449 security companies for buildings based in the United States

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Security companies for buildings based in the United States at a glance

As of Sep 6, 2026
11-50Median size (employees)
New YorkLargest hub · 114 HQs
64,122Contacts with mobile numbers
Sep 6, 2026Data refreshed

Companies by employee count

1-10
1,105
11-50
1,230
51-200
670
201-500
226
501-1,000
102
1,001-5,000
67
5,001-10,000
21
10001+
16

Verified emails by last verification

0–30
20,731
31–60
1,316
61–90
10
90–180
1
180+
379

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among security companies for buildings, so some rows will be adjacent to the category rather than pure plays. The description and evidence rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
What qualifies
Companies headquartered in the United States whose own description of what they do matches “security companies for buildings”. Matching reads each company's description, not its industry code or its name.
What we exclude
Companies whose own description does not clearly place them among security companies for buildings, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and an evidence rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every listed company carries at least one verified work email, 22,437 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on September 6, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Frequently asked

How many security companies for buildings are there based in the United States?

RevenueBase identified 3,449 security companies for buildings headquartered in the United States as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Allied Universal, headquartered in Irvine, tops this list with the largest team on record.

Which city has the most security companies for buildings?

New York leads with 114 headquartered companies, followed by Los Angeles (95) and Houston (75).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 22,437 verified decision-maker contacts tracked across these 3,449 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 6, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase SmartSearch, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.