Several home security systems don’t require a monthly fee for professional monitoring. These systems are usually self-monitored, which means the user, after installation, will receive notification alerts on their phone or email.   The user is responsible for taking the necessary steps when receiving a notification.   SimpliSafe: SimpliSafe is a popular home security system that offers affordable and customizable DIY systems. Its systems have various features, such as motion sensors, door and window sensors, and security cameras. SimpliSafe offers optional professional monitoring for a fee, but it’s not required. Ring Alarm: Ring Alarm is a DIY home security system that offers affordable and easy-to-install systems. Its systems have various features, such as motion sensors, door and window sensors, and video doorbells. Ring offers optional professional monitoring for a fee, but it’s not required. Abode: Abode is a DIY home security system offering various customizable systems. Its systems have multiple features, such as motion sensors, door and window sensors, and security cameras. Abode offers optional professional monitoring for a fee, but it’s not required.