Moved into a house with a burglar alarm and no codes?

By Ignis Secure. Published 19 October 2026.

The short answer

Ask the seller for the codes first, through your conveyancer or the estate agent. If that fails, an alarm engineer can usually reset the control panel, set new codes for you and service the system in one visit, so you know it works.

Even if you were given the codes, have them changed. You have no way of knowing who else has them.

Ask the seller first

The quickest fix is usually the seller. Before completion, ask through your conveyancer. Afterwards, the estate agent can normally pass a message on. Ask for:

• The user code, and the master or manager code if there is one
• The user guide for the alarm
• Any keyfobs, setting tags or remote controls
• The name of the company that installed or last serviced it, and when
• Whether it is monitored, has police response or is on a maintenance contract
• Whether it is linked to an app, and if so, for them to remove it from their account

The engineer code is different. It belongs to the company that installed or looks after the alarm, not to the homeowner, and sellers rarely have it.

Find out who installed it

The installer's name and phone number are usually on the outside bell box, and sometimes on a sticker on the keypad or in the user guide. If the company is still trading, it may be able to help. Some installers will release the engineer code or reset the panel once you show that you own or live in the property. Others prefer to send their own engineer.

If the company has stopped trading, the bell box has no name on it, or nobody answers the phone, another alarm engineer can take the system over.

Why you need new codes anyway

Even with a full set of codes, treat the alarm as someone else's until it has been reset. The previous owners, their family, cleaners, neighbours and keyholders may all know the code. Keyfobs and tags that were never handed back still work until they are deleted from the panel.

A proper takeover leaves you with new user codes, the old ones deleted, no keyfobs or tags registered that you don't hold, and none of the previous owner's phone numbers or app accounts still connected to the alarm.

How an engineer takes the alarm over

1. Identify the system. The make is usually printed on the keypad or the bell box. A photo of both helps the engineer bring the right parts.
2. Get engineer access. With the engineer code, this part is quick. Without it, many panels can be reset to factory settings, which clears the old codes, and then programmed again.
3. Set it up for you. New user codes, your own keyfobs or tags, entry and exit times that suit how you use the house, and a check that the movement sensors suit any pets.
4. Test and service everything. Every sensor, the backup battery, the bell box and any app or monitoring connection, finishing with a written report of what is fitted and what condition it is in.

The reset, the new codes and the service can usually be done in the same visit. After that, the alarm should be serviced once a year, or every six months if it is monitored. Our guide explains how often a burglar alarm should be serviced and what a service covers.

If the panel is locked

Some installers lock the control panel so that it cannot be reset to factory settings without their code. It protects their customers' systems from tampering, and it also stops another company taking the alarm over. A locked panel is the one case where a new owner cannot simply have the alarm reset. The options are:

• Ask the installer to unlock it or release the engineer code,. Some charge for this.
• Become the installer's customer and let them reset it and service it for you.
• Replace the control panel. If the installer cannot be reached or will not help, the panel can be replaced. On a wired alarm the cabling and most of the sensors can usually be kept, so it is not the same as starting again.

An engineer can tell whether a panel is locked at the start of the visit, so you know which of these applies before any work is done.

Monitoring, police response and apps

Monitoring and maintenance contracts

A monitoring or maintenance contract is between the previous owner and their alarm company. It does not pass to you with the house. The seller should cancel theirs, and if you want the alarm monitored, you take out your own. Once the old monitoring stops, the keypad may start showing a communication fault, which is one of the warnings covered in our guide to why a burglar alarm beeps.

Police response

Some alarms, mostly on businesses, are registered so that the monitoring centre can call the police. That police response does not carry on by itself when a property changes hands. The alarm company has to register the new occupier with the police, who charge an administration fee, and the alarm keeps any record of false alarms it already had.

Apps and smart alarms

If the alarm works with an app, the previous owner may still be able to see it, set it and get its notifications. Ask them to remove it from their account before you move in. If they can't or won't, tell the engineer, because cutting the old account off is part of the takeover. Some app-based systems can only be released by the manufacturer, which normally asks for proof that you now live there.

Home insurance

If you tell your insurer the house has an alarm, read the policy wording. Some policies expect the alarm to be set when the house is empty or to be professionally maintained, and a claim can be affected if it is not.

What not to do

• Don't try default codes from the internet. Installers almost always change them, and on many panels a run of wrong codes locks the keypad for a while or sets off a tamper alarm.
• Don't open the control panel to reset it yourself. On most systems that triggers a tamper, and on a locked panel the reset does nothing anyway.
• Don't cut the power to get rid of it. The backup battery keeps the panel running, and on most wired systems the outside bell box has its own battery and sounds if its wiring is cut. If you don't want the alarm at all, ask an engineer to decommission it.
• Don't rely on an alarm nobody has tested. If it has not been serviced for years, the backup battery may be flat, so it will fail the moment the power goes off.

Alarm with no codes in West London?

Ignis Secure is based in Uxbridge and takes over burglar alarms across West London, including systems fitted by other companies. Send a photo of the keypad and the bell box to us on WhatsApp so we know what you have, or see our burglar alarm servicing and repairs page. We have local pages for Uxbridge, Ruislip and Hayes.

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