If you have an intruder alarm…

…at your property, you’ll no doubt have come across the term ‘engineer code’, or the less common ‘installer code’. But what is an engineer code and what does it do?

In this article we break down what this code is used for, and why the secrecy around it.

Unique code

When your intruder alarm is installed, or when an existing alarm is taken over by a new company, it will be programmed with an engineer code that is unique to that company. This code grants full access to the system allowing the alarm company to make fundamental changes, such as adding or deleting user codes, or perform system maintenance. The user code or master manager code does not give this same level of access.


Because the engineer code allows such vast access to the alarm system, alarm companies will never give it out to anyone outside of the company. This is as much for your sake as it is theirs. For you, someone who gets hold of the engineer code could alter or disable your system leaving your property and its occupants vulnerable, invalidating your insurance policy, or voiding the system’s warranty. For the alarm company, it means they know your system will function as intended and, assuming they are NSI-accredited, that they are working within the standards they must adhere to.


Not knowing the engineer code for your system does not mean you cannot choose another company to takeover your alarm system, should you wish. Any reputable company will reset your system to the default settings if you choose to leave them. Likewise, any competent alarm installer will be able to default your system and input their own engineer code in the event of a takeover.


There are some systems that are ‘closed-protocol’, meaning they can only be controlled or serviced by the company that installed them. These, however, are uncommon and CIA Fire & Security will never install one of these closed-protocol systems.

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