No Landline? Use Cellular Backup to Connect

Learn how ADT CellGuard cellular backup helps keep your alarm system connected to ADT monitoring when your phone line goes down.

Author: ADT Security Services

Publish Date: 06/16/2025

Reading time: 2 Min

Key takeaways

ADT CellGuard sends alarm signals to ADT's monitoring centers over a cellular network when your phone line or digital voice line is down.
It helps keep your system connected during outages caused by storms, accidents, cut lines, construction or provider issues.
CellGuard can serve as a backup to your phone line or, where local rules allow, as your system's only communication path, so you may not need a landline.
No separate cellular contract is needed. CellGuard is covered under your ADT Residential Services Contract.

One of the most vulnerable components of the security system at your home is the telephone or digital voice line that provides primary communication between your system and ADT’s Customer Monitoring Centers. That’s why we offer you a backup solution – Safewatch Cellguard®.

In the event of a telephone or digital voice line outage, Safewatch Cellguard can transmit alarm signals to an ADT Customer Monitoring Center through a cellular network, helping prevent a lapse in your security service. Safewatch Cellguard can help back up the ADT security system if your telephone or digital voice service is disrupted due to:

Storms
Accidents
Fallen lines
Construction
Cut lines
Other communication-provider issues

Safewatch Cellguard can also serve as the sole means of communication between your home and ADT’s network of interconnected Customer Monitoring Centers, which can save you money if you decide to cancel your landline phone.

FAQs about Safewatch CellGuard

How does Safewatch Cellguard work?

In the event of a telephone or digital voice line outage, or if the phone line associated with the alarm panel is not functioning properly, Safewatch Cellguard can transmit signals through a cellular transmission wireless network.

Is Safewatch Cellguard active when phone lines are working?

No. The use of Safewatch Cellguard does not preclude the use of the telephone line. The phone line will remain the primary means of communication.

Is Safewatch Cellguard always a backup method of alarm system communication?

No. Safewatch Cellguardcan be installed as the security system’s sole or primary means of communication with ADT’s Customer Monitoring Centers. Local restrictions apply. Your ADT Representative can provide you information to help you determine the appropriate home security system configuration.

Does Safewatch Cellguard work in the event of a power outage?

Yes, this is another important benefit of Safewatch Cellguard.

Do I have to sign a cellular contract?

No contract is necessary other than ADT Residential Services Contract. There is no need to set up any cellular service with a third-party supplier.