The short answer
It is wise to, and sometimes you must. Installing a burglar alarm is generally a security improvement, not a risk you are obliged to volunteer mid-term — fitting one rarely breaches a policy. However, if your insurer asked about alarms when you took out the policy, or your renewal questions ask about security, you should give an accurate answer, because answering a direct question wrongly is a misrepresentation that can affect a claim. Telling the insurer can also work in your favour: it may earn a small discount where one is offered. The trade-off is that once declared, the alarm may attract an alarm condition requiring it to be set and maintained. So the safe approach is to be accurate on any security question and to update the insurer at renewal.
Disclosure rules in UK insurance turn on the questions the insurer asks. Fitting an alarm is usually positive, but how and when you mention it still matters.
Telling your insurer about an alarm
- Obliged to volunteer mid-term?Usually no
- Must answer questions accurately?Yes
- Possible benefitSmall discount
- Possible conditionAlarm warranty
- Best time to updateAt renewal
How UK disclosure rules work
Under modern consumer insurance law, the duty on a policyholder is to take reasonable care not to make a misrepresentation — in practice, to answer the insurer's questions honestly and accurately. This replaced the older, harsher duty to volunteer everything that might be 'material'. The key consequence is that what you must tell the insurer is largely shaped by what it asks.
Installing a burglar alarm reduces risk rather than increasing it, so it is not the kind of change that typically breaches a policy if you do not announce it the moment it is fitted. But if the insurer's application or renewal asks 'do you have a burglar alarm?' or about your security arrangements, you must answer correctly. Saying you have an alarm when you do not — or describing it inaccurately — is a misrepresentation that could affect a future claim.
Why telling the insurer can help — and what it changes
There are two practical reasons to mention a new alarm even though you may not be strictly obliged to mid-term. First, it can produce a small discount on policies that give alarm credit, particularly for an NSI- or SSAIB-approved, maintained system. Second, it ensures your records are accurate, so there is no later argument about whether the insurer knew about the alarm.
The flip side is that disclosing an alarm can change your policy conditions. Once an insurer knows you have one — and especially if it gives a discount — it may add an alarm warranty requiring the system to be operational, set when the home is unoccupied, and maintained. That is not a reason to hide the alarm; it is simply a reason to understand that declaring it can come with an obligation to use it properly.
| Action | Effect |
|---|---|
| Fit alarm, say nothing mid-term | Usually fine — alarm reduces risk |
| Answer a security question accurately | Required; protects future claims |
| Declare alarm for a discount | May earn a small saving |
| Declare alarm | May attach an alarm condition |
| Misstate having/maintaining an alarm | Misrepresentation; can affect a claim |
Indicative outcomes. Your duty is accuracy on the insurer's questions; benefits and conditions vary by insurer.
Handling it at renewal
Renewal is the natural moment to bring the insurer up to date. Many insurers ask you to confirm that the information they hold is still correct, and renewal questions may cover security. Use that opportunity to state that you now have an alarm and to describe it accurately — for example, whether it is professionally installed and maintained, and whether it is bells-only or monitored.
If you want the alarm to be recognised for any discount, this is also when to ask what the insurer would offer and what conditions would apply. Keep your installation certificate and maintenance contract to hand in case the insurer wants confirmation. If a discount comes with an alarm condition, make sure you can realistically meet it — setting and maintaining the alarm — before accepting it, because an unmet condition can undermine a theft claim later.
If you are unsure
If you cannot tell whether your policy expects you to mention the alarm, the simplest safe step is to ask the insurer or read the section of the policy dealing with changes to your circumstances and security. Some policies specifically ask to be told about changes to security or about new alarms; others do not. Following the policy's own instructions removes any doubt.
As a general rule, you will not go wrong by answering every security question accurately and updating the insurer at renewal. That satisfies your duty under consumer insurance law, keeps your records straight, and gives you the chance to benefit from any discount on offer. Because insurers word their questions and conditions differently, and the rules can change, confirm anything you are unsure about directly with your own insurer rather than relying on a general summary.
The same principle applies if you later change or remove the alarm. If you declared a monitored, maintained system and then let the monitoring contract end, switch to a bells-only setup, or stop servicing it, the picture the insurer holds is no longer accurate. Where a security question was asked and answered, a material change of that kind is worth telling the insurer about, especially if the alarm formed part of why cover was offered or a discount was given. Keeping the insurer's record in step with reality protects you twice over: it avoids any later suggestion that you misrepresented your security, and it ensures the conditions attached to your policy still match the system you actually have. A short note or call at renewal, or whenever the system materially changes, is usually all it takes.
Frequently asked questions
Will I breach my policy if I don't mention a new alarm mid-term?
Usually not. An alarm reduces risk, so fitting one is not the kind of change that typically breaches a policy. The important duty is to answer any security questions accurately when asked, including at renewal.
Could telling the insurer make my policy stricter?
It can. Declaring an alarm may attach an alarm condition requiring it to be set and maintained when the home is empty. That is not a reason to hide it, but a reason to make sure you can meet the condition before accepting any discount.
When is the best time to tell my insurer about an alarm?
At renewal, when many insurers ask you to confirm your details are correct. State that you now have an alarm, describe it accurately, and ask what discount and conditions apply if you want it recognised.
Sources & further reading
- Financial Ombudsman Service — non-disclosure and misrepresentation
- Association of British Insurers (ABI) — home insurance guidance
Figures on this page are typical UK ranges drawn from published sources and depend on your specific property and system. They are guidance, not a quotation.