What ADT does and how it fits into your home

ADT is a home security company that monitors your house for break-ins, fires, and carbon monoxide leaks. When a sensor detects a problem — a door opening, smoke, or a gas alarm — it sends a signal to ADT's monitoring center. An operator there can contact emergency services on your behalf, call you to confirm it's a real emergency, or both.

ADT has been in the security business since 1874, so it's one of the older names in the field. The company offers both monitored systems (where ADT watches your home 24/7) and unmonitored systems (where you get alerts but handle the response yourself). Most people who choose ADT go for the monitored option because the whole point is having someone else call 911 if you're not home.

The system itself is a network of sensors placed on doors and windows, motion detectors inside, and a control panel (usually a keypad or touchscreen) that arms and disarms the system. You can control it from your phone, a keypad, or a key fob. If you add cameras, you can watch live video from anywhere.

Key Takeaways

  • ADT monitors your home 24/7 through sensors on doors, windows, and motion detectors that alert the company's call center if something triggers them.
  • You pay a monthly monitoring fee (separate from equipment costs) for ADT to respond to alerts and contact emergency services if needed.
  • Installation can be done by ADT technicians or, with some plans, you can install equipment yourself and still get professional monitoring.
  • ADT contracts typically run 24 to 36 months, and early cancellation usually comes with a penalty fee that varies by contract length.
  • You can add cameras, smart locks, and environmental sensors (smoke, carbon monoxide, water leak detection) to expand what the system covers.

How the monitoring service actually works

When a sensor is triggered — say a window breaks or motion is detected inside — the control panel sends a signal to ADT's monitoring center. An operator receives the alert and checks what type of sensor triggered it. If it's a door or window, they'll call you at the phone number on file to confirm whether it's a real emergency.

If you don't answer, or if you confirm there's a break-in, the operator dispatches police to your address. For fire or carbon monoxide alerts, they typically dispatch fire services without waiting for confirmation, since those are life-threatening. The whole process usually takes a few minutes from alert to dispatch.

You can also trigger the system manually using a panic button on your keypad or phone app if you feel unsafe. This sends an when ready alert to the monitoring center without waiting for a sensor to detect anything.

Equipment, installation, and what it costs

ADT charges two separate costs: equipment and installation upfront, then a monthly monitoring fee. Equipment prices vary depending on what you choose — a basic system with a control panel, door/window sensors, and a motion detector might run $200 to $400. Adding cameras, smart locks, or environmental sensors increases the upfront cost.

Professional installation by an ADT technician typically costs $100 to $300, though some promotions waive this fee. If you choose a self-install option (available on certain plans), you set up the equipment yourself and skip the installation fee, but you still pay for the equipment and the monthly monitoring.

Monthly monitoring fees range from roughly $25 to $60 depending on the plan and how many features you add. Some plans include cameras or smart home integration; others are basic door and window monitoring only. Longer contracts (36 months) sometimes offer lower monthly rates than shorter ones (24 months).

Contracts and what happens if you want to cancel

ADT typically requires a contract of 24, 36, or sometimes 48 months. This means you're committing to pay the monthly fee for that entire period. If you cancel early, you owe an early termination fee — usually calculated as the remaining balance of your contract. For example, if you're 12 months into a 36-month contract at $40 a month, you'd owe roughly $960 (24 months × $40) to cancel.

Some promotions offer shorter contracts or month-to-month options, but these usually come with higher monthly rates to offset the company's risk. It's worth asking about contract length when you're comparing quotes, because the termination fee can be substantial if your situation changes.

If you move, you can sometimes transfer your service to a new address, though this may require a new installation fee. Check your contract or ask ADT directly about relocation policies before you sign.

Arming, disarming, and controlling the system from your phone

You arm the system using a code on your keypad, a key fob, or the ADT mobile app. Most systems have multiple modes: "Away" (all sensors active), "Home" (perimeter sensors active, but interior motion detectors off so you can move around), and "Disarm" (system off). Some newer systems let you set custom modes or schedules.

The ADT app shows you the status of your system, lets you arm or disarm remotely, and sends you notifications when doors open or motion is detected. You can also see live camera feeds if you've added cameras. The app works over your home internet connection, so if your internet goes down, you lose remote access — but the system itself keeps working and still sends alerts to ADT's monitoring center.

If you forget your code, you can reset it through the app or by calling ADT customer service. Most systems also have a master code that only you know, which you can use to create additional codes for family members or service providers.

Adding cameras, smart locks, and other sensors

Beyond basic door and window sensors, ADT lets you add indoor and outdoor cameras, smart door locks, glass break detectors, and environmental sensors for smoke, carbon monoxide, and water leaks. Cameras record to the cloud (ADT's servers) and you can watch live video or recorded clips through the app. Smart locks let you lock or unlock doors remotely and create temporary codes for guests or service people.

Each add-on increases your upfront equipment cost and may increase your monthly monitoring fee slightly. Some plans bundle cameras and smart locks together at a discount. Environmental sensors are often cheaper to add than cameras but provide different kinds of protection — a water leak sensor, for instance, can alert you to a burst pipe before it floods your basement.

Not all add-ons are compatible with all ADT plans, so check what's available on the specific package you're considering. You can usually add devices later if you start with a basic system and decide you want more coverage.

How ADT compares to other monitoring companies

ADT is one of the largest and oldest security companies, which means it has monitoring centers in most areas and a long track record. However, it's not the only option. Vivint, Frontpoint, Moni, and others also offer 24/7 monitoring, and some have lower monthly fees or shorter contract terms. Some companies specialize in self-install systems, which can be cheaper upfront.

The main trade-off is usually between price and convenience. ADT's professional installation and large network mean you're paying more, but you get a system set up by someone who knows what they're doing. Smaller or newer companies may charge less but offer fewer customization options or slower customer service.

If you already use other smart home devices (like Amazon Alexa or Google Home), check whether the system you're considering integrates with them. Some ADT plans do; others don't. This can matter if you want your security system to work alongside other smart home automation.

Frequently Asked Questions

What happens if my internet goes down?

Your ADT system keeps working and still sends alerts to the monitoring center through a cellular backup connection (included in most plans). You just won't be able to access the system remotely through your phone app until your internet is back. The monitoring service itself doesn't depend on your home internet.

Can I take my ADT system with me if I move?

You can transfer service to a new address, but ADT may charge a relocation or reinstallation fee. Some equipment (like the control panel) is portable; other parts (like wired sensors) may need to be reinstalled by a technician. Contact ADT before you move to understand the costs and process.

Do I need a landline for ADT to work?

No. Modern ADT systems use cellular backup to contact the monitoring center, so you don't need a landline. Older systems sometimes required one, but current equipment doesn't. Your home internet connection is useful for remote access through the app, but not required for the monitoring service itself.

What if there's a false alarm?

If you accidentally trigger the alarm, you can disarm it using your code before the monitoring center calls. If they do call and you confirm it's a false alarm, no emergency services are dispatched. However, repeated false alarms may result in fees from your local police department, not from ADT — check your city's false alarm policy.

Can I monitor multiple properties with one ADT account?

You can set up separate systems at different addresses, but each one requires its own contract and monthly fee. You can view all of them through one app account if you link them together. This is useful for rental properties or a vacation home, though the cost adds up quickly.