The SOCAL Security Experts Since 1956.

Family-owned businesses depend on client satisfaction, and we’ve been listening to our clients for over 60 years. When they talk, we listen, and listening has allowed us to become the most trusted name in security in Southern California.

Modern Home Security

Welcome to a new generation of home security, automation, mobile control, and peace of mind.
Welcome to Post Alarm.

Custom Business Solutions

Our highly trained team will custom design, install and support a full range of Security, Video, Access and Fire solutions to meet your specific needs.  Whether you own a small retail store or manage multiple businesses across California, our experts have you covered.  

Residential Patrol

Post Alarm’s highly trained Armed Patrol and Alarm Response Officers put you first and get help there quickly, often eliminating false alarm fines, and alerting the police when a real need arises.

24/7 Alarm Monitoring

Post Alarm owns and operates it’s own UL Listed, CSAA 5 Diamond Central Station to provide personalized services and deliver an authentic unified solution.

Family Owned & Operated Since 1956

Owned and operated by the Post Family for over 60 years, we have become one of the largest, most respected full-service security companies in Southern California.

Complete commercial, home security & alarm monitoring in Los Angeles, Orange County, and SOCAL since 1956.


We’ve been in the security business for over 60 years and we’ve seen firsthand the happiness that comes when our clients feel safe in their homes. That’s why we offer custom designed, interactive security solutions with leading technology and service.


To protect your commercial business from theft, vandalism, or fire, our trained technicians will custom-design a system that uses cutting edge technology to manage all your security needs. We are here for you and your business all day, every day.

"We highly recommend Post Alarm to any homeowner considering an alarm system. The people, service, and products are second to none!"

D&M Weaver | Monrovia, CA
Clients Since 2009


Our unique security analysis process provides a personalized plan for your business or family’s needs.

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