Family, Integrity,
Community... Since 1956

Post Alarm leverages the latest home security technology to keep your family safe—a promise we take seriously as a responsive, family-run business right in your neighborhood.


Our mission is to keep your home and your family safe. From the people we hire to the systems we install, every aspect of our business is designed to protect what is most valuable to you. With a team of over 100 employees dedicated to serving your security needs, we treat every client as a priority each and every day.


For over three generations, we’ve been keeping people safe. We take pride in our long tradition of providing uncompromising service focused on protecting clients and their valuables and extend our family-style commitment and care to every customer we serve.


Unlike other larger security providers, we care about keeping the community safe because we are part of the very community we serve. Thus, investing in our community is one of our top priorities.


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. We endeavor to keep our clients and their valuables safe, and will do everything in our power to make that happen.


When Sam Post founded our company in 1956, he wanted to help make Southern Californians safer by providing premier security services to area businesses and individuals. As a former police chief, Sam valued what a sense of security could bring to the community. As demand for home security systems grew in the 1970s, Post Alarm Systems, under the leadership of Sam’s son Bill and his wife Lois, became the go-to company for alarm systems and patrol services.

As clients began telling friends about Post Alarm’s excellent service, we saw continued growth and increased client satisfaction. Today, Post Alarm has over 125 team members who still provide the level of client service that has been associated with our company since its inception.

By supplying new service offerings and leading the way in the ever-changing world of security technology, we’ve managed to provide the best security to businesses and individuals while keeping our core values anchored to our brand. We’ve always been a local, family-owned company, and we’re going to stay that way.

Now in our third generation of family ownership under Rob Post and Gina Post-Franco, Sam Post’s approach to keeping people and property safe still echoes in the way we do business. His philosophy was straightforward and simple: “Take care of every client properly. Every time. Without exception.”

Our company was founded on a passion for protecting people, and that passion is what makes Post Alarm Systems the best in the business today.


We believe that your security system is only as good as the people you are trusting to monitor it.

Post Alarm’s local professional monitoring is what separates us from the pack. We own and operate our own in-house Central Station and personally monitor every alarm or alert sent from your system. Our locally-based Monitoring Station has earned the industry’s highest distinctions: UL and Five Diamond certification. Translation: highly trained, real people actively working within the system guarantees greater security and faster response from the proper authorities. Whether you’re at home or away, our professional monitoring staff keeps watch over your home 24 hours a day, 7 days a week, 365 days a year.

Post Alarm is proud to be one of the few alarm companies in the United States to have achieved both UL and Five Diamond certifications for our monitoring services. These certifications guarantee the highest standards of reliability and professionalism for all our security offerings. For us, these certifications mean hours of extra training, verification of system redundancies and uptime, and random inspections of our central station to verify that we are at the top of our game. To our clients, these certifications indicate our commitment to going the extra mile and guaranteeing the highest level of service. It means that our clients can rest easy knowing that Post Alarm is watching out for them and is backed by the industry’s highest quality and reliability standards.

Post Alarm certifies that it holds the following:

  • Alarm License: ACO1843
  • C-10/C-7 License: 670585
  • Patrol License: PPO10170
  • Alarm Company Qualifications: ACQ406
  • Private Patrol: 577900-20

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

- Brian

“Safety is ultimately up to you. The best you can do is harden the target. That’s what Post Alarm provides. They are a minute away. Post Alarm is a brand known and respected.”

- Glenn

“What I love most about Post Alarm is their ability to accommodate our business needs.”

- Tammy

“I’ve been a Post Alarm customer for over 40 years, and have never had a complaint or fault with any of their services.”

- Robert

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