Although ADT makes more than two dozen different models of home security alarms, the procedure for changing the master code differs very little between them. When your alarm is installed, the installer will issue an initial four-digit master code. If you would like a more secure code, or one that is easier to remember, you can enter a custom master code into the system. You can also issue temporary codes that can arm/disarm the alarm, but can't change any alarm settings. These codes can easily be deprogrammed.
Change the master code by entering the [four digit master code]+++[new master code]. If successful, the keypad will beep once.
Set up a temporary code by first entering your master code, then pressing the "Code" key. Press a single digit between 1 and 7 to designate the code. Enter a four-digit code for that temporary user. A beep means you entered the code correctly. To delete a temporary code, follow the steps above. After a few seconds, the system will beep, signifying the code was erased.
Assign a duress code to be used in the event that someone is forcing you to enter the code. When you enter the duress code, the system will operate normally, but the police will be silently notified. Enter the [master code]+++[duress code]. The keypad will beep once when the operation is successful.
Test all the codes to ensure they work correctly.
You can find a manual for your specific ADT system in the reference section below.
Never give out the master code to anyone. Always use a temporary password. Never use a code associated with you, such as your birthday.