Let's Protect What Matters
Speak directly with our Monrovia headquarters. We answer calls live during business hours and dispatch 24/7 for monitoring customers.
Call Us
Fastest response — speak with a live specialist now.
(800) 833-6068
Email Us
Send project details or questions — we reply within one business day.
info@usaalarmsystems.com
Free Consultation
Tell us about your property — get a tailored recommendation, no obligation.
Request a Quote
Headquarters
138 E. Chestnut Ave.
Monrovia, CA 91016
Toll Free
General Inquiries
Hours & Dispatch
Existing monitoring customers: Call (800) 833-6068 for immediate alarm support. Our dispatch team is standing by 24/7.
Trusted by SoCal Businesses & Homeowners
Don't just take our word for it. Here's what our customers say about working with USA Alarm Systems.
Simply the best! We have been with them for years. Our son also uses them. No comparison. If you are looking for a great alarm company this is it. Personal service. Great techs.
Fantastic local company. Always responsive to our needs. Their technicians are professional and knowledgeable — thank you for all you do.
USA Alarm Systems has protected our commercial property for over a decade. Their technicians understand our building and always respond quickly when we need service.
Professional, reliable, and local. They upgraded our entire fire alarm system with zero downtime. Highly recommend for any Los Angeles business.
We switched from a national company and the difference is night and day. Real people, real local technicians, and real service when it matters.
Their team designed a custom security system for our warehouse and office. The installation was clean and the monitoring has been flawless.
Decades of experience shows. They knew exactly what our building needed to meet code and passed inspection on the first try.
Best alarm company in the San Gabriel Valley. Responsive, professional, and they actually answer the phone when you call.
From design to installation to monitoring, USA Alarm Systems handled everything for our multi-location business. One call does it all.
Their local knowledge of LA County fire codes and permit requirements saved us months of headaches. True professionals.
Simply the best! We have been with them for years. Our son also uses them. No comparison. If you are looking for a great alarm company this is it. Personal service. Great techs.
Fantastic local company. Always responsive to our needs. Their technicians are professional and knowledgeable — thank you for all you do.
USA Alarm Systems has protected our commercial property for over a decade. Their technicians understand our building and always respond quickly when we need service.
Professional, reliable, and local. They upgraded our entire fire alarm system with zero downtime. Highly recommend for any Los Angeles business.
We switched from a national company and the difference is night and day. Real people, real local technicians, and real service when it matters.
Their team designed a custom security system for our warehouse and office. The installation was clean and the monitoring has been flawless.
Decades of experience shows. They knew exactly what our building needed to meet code and passed inspection on the first try.
Best alarm company in the San Gabriel Valley. Responsive, professional, and they actually answer the phone when you call.
From design to installation to monitoring, USA Alarm Systems handled everything for our multi-location business. One call does it all.
Their local knowledge of LA County fire codes and permit requirements saved us months of headaches. True professionals.
Ready to Secure Your Property?
One call does it all. From design to installation to monitoring — our licensed Southern California team is ready when you are.