How long do I have to cancel a false alarm?

It depends on the provider and setting. ADT documents a 30 second window to enter your security code before the monitoring center treats it as an emergency, and its smoke alarm abort window defaults to 30 seconds. SimpliSafe describes a brief false alarm grace period for entry, motion, and glass break sensors. Disarming inside the window closes the event without a call or dispatch.

Will police automatically show up when my alarm goes off?

Not immediately. For burglary alarms, monitored providers first try to reach you and your emergency contacts, and only request police dispatch if nobody answers, someone gives the wrong verbal password, or someone asks for help. Some jurisdictions also require verification (video or a guard) before police respond, and many require an alarm permit.

What is a verbal password or safe word?

A phrase you set with the monitoring center, separate from your keypad code, used to verify your identity on the phone. You need it to cancel an alarm or discuss the account. If you give the wrong one, providers dispatch without telling you it was wrong, in case an intruder is forcing you to answer.

What happens if my alarm goes off and I do nothing at all?

The monitoring center works its contact list, then requests dispatch. Ring documents police dispatch when no contacts answer; ADT contacts authorities after both primary and secondary contacts fail. With a self-monitored system, nothing happens beyond the siren and phone notifications; no one is coming unless you call them.

Can I cancel a fire or CO alarm the same way as a burglar alarm?

Fire alarms are cancellable in most areas by answering the monitoring call, and SimpliSafe does not require a Safe Word for smoke alarm cancellation. CO alarms generally cannot be cancelled at all; SimpliSafe and Ring both dispatch immediately due to the health risk. Some jurisdictions dispatch fire first and only update responders if you report a false alarm.

What Happens When Your Alarm Goes Off?

With professional monitoring, a triggered alarm sounds the siren, sends the signal to a monitoring center, and starts a short grace window (ADT's is 30 seconds) in which you can disarm with your code and end the event. If you do not, the monitoring center calls you and your emergency contacts; whoever answers must give a verbal password to cancel. If nobody answers, the password is wrong, or anyone requests help, the center requests police dispatch. Fire, carbon monoxide, panic, and duress alarms follow faster, stricter flows.

Figures researched 2026-08-19; each source below carries its access date. Prices change; treat any price here as "as of" its date.

The standard burglary alarm sequence

The three biggest consumer monitoring providers document nearly the same escalation ladder. Composite of their official support documentation, as of August 2026:

A sensor trips (door, window, motion, or glass break) while the system is armed. The siren sounds and the signal goes to the monitoring center. SimpliSafe says its monitoring center is informed immediately and you get an app push notification and/or alarm text at the same time.
Grace window. You have a brief period to disarm with your code, keypad, fob, or app. ADT's documentation puts this at 30 seconds; SimpliSafe calls it a false alarm grace period. Disarm inside the window and the event is closed as a false alarm, with no call and no dispatch.
Contact calls. If the alarm is not cancelled, the center calls the primary contact. ADT: if the primary contact verifies with the correct verbal security password, they can cancel or request help; if unreachable or the password is wrong, ADT calls the secondary contact, and if that also fails, contacts the authorities. Ring's version: police dispatch is requested when no contacts answer, when a contact does not know the verbal password, or when any contact asks for help.
Dispatch. The monitoring center requests emergency response from your local police (in some jurisdictions a guard responder first; see below). Contacts designated as courtesy or post-dispatch contacts are notified after the fact and cannot cancel.

Two details people consistently get wrong. First, the verbal password (SimpliSafe calls it a Safe Word) is separate from your keypad code, and giving a wrong one triggers dispatch without the operator telling you it was wrong, a deliberate protection in case you are under duress. Second, per Ring, no password is needed to request dispatch, only to cancel; the system is biased toward sending help.

Fire, CO, panic, and duress alarms work differently

Life-safety alarms compress or skip the verification ladder.

Alarm type	What providers document
Smoke or fire	SimpliSafe calls only the first primary contact because time is critical, and no Safe Word is needed to cancel. Ring calls the primary contact, then dispatches the fire department if there is no answer. ADT notes jurisdiction exceptions: in New York state and some cities the fire department is dispatched first and cannot be cancelled, only updated.
Carbon monoxide	Effectively no cancellation. SimpliSafe dispatches emergency services and calls you simultaneously, and states there is no way to cancel a CO alarm. Ring immediately requests fire department response, then informs contacts.
Panic button	Immediate escalation. ADT's emergency buttons dispatch on signal receipt with no phone call and no cancellation. Ring calls only the primary contact, and dispatches if they confirm, answer wrong, or do not answer.
Duress (silent)	Entering a duress PIN disarms the system locally but silently requests police dispatch. SimpliSafe documents that you receive no push notification, alarm text, or call from the monitoring center. Ring documents that your emergency contacts will not be called and that the dispatch cannot be cancelled.

If you are comparing systems, it is worth reading each provider's response-plan page for these edge cases; they differ more on life safety than on burglary handling.

Verification, guards, and false alarm exposure

Some cities require verification before police will roll on an alarm. Ring documents a Guard Response service that sends a trusted guard to verify the emergency first, noting that in some areas police and fire departments require certain signals to be verified before responders can be dispatched. ADT similarly enrolls customers in Alarm Messenger with video verification, texting you and your contacts simultaneously when a burglar alarm triggers. ADT's fire flow can also send a patrol agency first to verify, and in Las Vegas, North Las Vegas, and Henderson, Nevada, fire must be visually verified before fire dispatch.

The cost angle: both ADT and Ring warn in their official documentation that false alarms may draw fines from your local municipality or police department, and Ring's fine print adds that permit fees may be required depending on jurisdiction. Many cities require an alarm permit before police will respond at all, so check your city's ordinance when you set up monitoring.

One honest caveat about self-monitored setups: this entire escalation ladder only exists if a monitoring center is on the other end. ADT states plainly that for self-monitored customers the emergency button plays an audible alarm but does not notify ADT or emergency services. With self-monitoring, the alarm notifies you, and calling 911 is your job. Whether that trade-off is acceptable is the core question in is professional monitoring worth it. If you decide you want a monitoring center behind your system, our short questionnaire at /quote fetches real quotes from professional monitoring providers, and home security cost per month covers what the ongoing fee buys.

Frequently asked questions

How long do I have to cancel a false alarm?: It depends on the provider and setting. ADT documents a 30 second window to enter your security code before the monitoring center treats it as an emergency, and its smoke alarm abort window defaults to 30 seconds. SimpliSafe describes a brief false alarm grace period for entry, motion, and glass break sensors. Disarming inside the window closes the event without a call or dispatch.
Will police automatically show up when my alarm goes off?: Not immediately. For burglary alarms, monitored providers first try to reach you and your emergency contacts, and only request police dispatch if nobody answers, someone gives the wrong verbal password, or someone asks for help. Some jurisdictions also require verification (video or a guard) before police respond, and many require an alarm permit.
What is a verbal password or safe word?: A phrase you set with the monitoring center, separate from your keypad code, used to verify your identity on the phone. You need it to cancel an alarm or discuss the account. If you give the wrong one, providers dispatch without telling you it was wrong, in case an intruder is forcing you to answer.
What happens if my alarm goes off and I do nothing at all?: The monitoring center works its contact list, then requests dispatch. Ring documents police dispatch when no contacts answer; ADT contacts authorities after both primary and secondary contacts fail. With a self-monitored system, nothing happens beyond the siren and phone notifications; no one is coming unless you call them.
Can I cancel a fire or CO alarm the same way as a burglar alarm?: Fire alarms are cancellable in most areas by answering the monitoring call, and SimpliSafe does not require a Safe Word for smoke alarm cancellation. CO alarms generally cannot be cancelled at all; SimpliSafe and Ring both dispatch immediately due to the health risk. Some jurisdictions dispatch fire first and only update responders if you report a false alarm.

Sources

SimpliSafe burglary alarm flow: immediate monitoring center notification, grace period, Safe Word, dispatch if contacts unreachable; smoke calls first primary contact only; CO cannot be cancelled; duress sends no notifications: https://support.simplisafe.com/articles/alarm-event-monitoring/what-happens-during-an-alarm (accessed 2026-08-19)
ADT: 30 second cancel window, verbal security password, primary then secondary contact then authorities, courtesy contacts cannot cancel, emergency buttons dispatch without call, false alarm fine warning, Alarm Messenger with video verification, fire dispatch jurisdiction exceptions, self-monitored emergency button does not notify ADT or emergency services: https://help.adt.com/article/adt-Smart-Home-Security-What-to-Do-in-the-Event-of-an-Alarm (accessed 2026-08-19)
Ring: dispatch conditions (no answer, wrong verbal password, help requested), no password needed to request dispatch, Guard Response verification in jurisdictions requiring it, smoke and CO and panic and duress and SOS response plans, permit and false alarm fee fine print: https://ring.com/support/articles/7hiub/Ring-Alarm-Professional-Monitoring-Emergency-Response (accessed 2026-08-19)