How to change an alarm code for home security

Home alarm systems are a popular security measure used by many homeowners. From time to time it may be necessary to change the alarm code to maintain your family's security. Changing an alarm code often varies in difficulty depending upon the type of alarm installed in your home.

Locate the master code needed to change your alarm code. The master code is set by the security company when the alarm is installed into the house. If the master code was not written on a card by the technician he may have written it inside the owner's manual.

Consult your owner's manual for step-by-step instructions on how to change an alarm code. Depending on the type of home security system is installed in your house you will need to either press the "Reset" button or "#9" on the keypad. When prompted (usually by three beeps) enter your current alarm code followed by "#" and then the master code. Once you have entered the master code you will be able to enter your new alarm code.

If you cannot locate your owner's manual or are unsure of the steps that must be followed to change your alarm code call your monitoring company. They will be able to walk you through the process of resetting your alarm code once they verify the type of alarm system installed in your home. You will still need to have your master code available since your alarm monitoring company will not be able to provide it over the phone.

If you are unable to locate your master code or are not comfortable changing your alarm code by yourself request a service call from a technician. Depending on what home security company you are currently using you may be able to request a limited number of free service calls each year. During the service call the technician will be able to completely reset your master code (if you cannot locate it) and change your alarm code.


Do not attempt to change an alarm code without an owner's manual or master code. Write down your new alarm code immediately and provide it to any family members who still have the old alarm code.

Things You'll Need

  • Master code
  • Owner's manual
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About the Author

Tameka McSpadden is a freelance writer with several years of professional experience. With both a Bachelor of Science in health care management and an associate degree in business administration from Bellevue University, McSpadden enjoys writing about all medical topics. She is currently preparing for a literary agency internship in North Georgia while attending various writing workshops.