The short answer
Only if your insurer says so. Many UK homes are insured without any alarm at all, so an NSI- or SSAIB-approved system is not a universal requirement. Where an insurer does ask for an alarm — typically for high-value contents, valuables or higher-risk properties — it usually wants one installed and maintained by an approved company. NSI (National Security Inspectorate) and SSAIB (Security Systems and Alarms Inspection Board) are the two recognised UK certification bodies for security installers, and an approved installation comes with paperwork the insurer can rely on. If your policy carries no alarm condition, a DIY or non-approved alarm can be perfectly acceptable — it simply earns little or no insurance credit. The deciding factor is the wording of your own policy.
NSI and SSAIB approval is a quality marker for security installers, not a legal standard every household must meet. Whether you need it depends on what your insurer requires.
NSI / SSAIB approval and insurance
- NSINational Security Inspectorate
- SSAIBSecurity Systems & Alarms Inspection Board
- Universal requirement?No
- When expectedHigh value / high-risk policies
- DIY alarmAllowed, little insurance credit
What NSI and SSAIB approval actually means
NSI and SSAIB are the two main UK bodies that certify security and fire installation companies against recognised standards. An installer holding approval has been assessed for competence and quality, works to the relevant British and European standards for intruder alarms, and issues a certificate of installation for each system. For an insurer, that certificate is valuable: it confirms the alarm was designed and fitted to a known standard, rather than assembled and self-installed to an unknown one.
The two bodies serve a similar purpose, and most insurers that ask for an approved alarm accept either. The point is not the badge itself but what it represents — a professionally specified, installed and documented system that the insurer can treat as a genuine, verifiable security measure.
When an insurer requires an approved system
For an ordinary home with modest contents, most insurers do not insist on an alarm of any kind, let alone an approved one. The requirement tends to appear where the risk or value is higher:
- a large contents sum insured or specified high-value items such as jewellery, watches or art;
- a property in a higher-crime area or one the insurer rates as more exposed;
- non-standard, high-value or unoccupied properties;
- cover for valuables kept at home, where an approved alarm may be a condition for those items.
In these cases the policy may state that the alarm must be installed and maintained by an NSI- or SSAIB-approved company. If that condition applies and is not met, the related theft claim can be affected, so it is worth confirming the exact requirement before fitting a system.
| Alarm type | Typical insurance recognition |
|---|---|
| NSI- or SSAIB-approved, maintained | Accepted; may attract a discount |
| Professionally fitted, not approved-body certified | Sometimes accepted; depends on insurer |
| DIY / self-installed | Allowed but little or no credit |
| No alarm | Fine where the policy has no condition |
Indicative guide to how UK insurers view different alarm types. Confirm with your own insurer.
Can I use a DIY or non-approved alarm?
Yes, in most cases. Unless your policy specifically requires an approved system, you are free to fit a DIY or self-monitored alarm, and it can still deter intruders effectively. What it will not usually do is earn an insurance discount or satisfy an approved-installer condition where one applies. Insurers give little credit to DIY systems because they cannot verify the specification, the installation quality or the upkeep.
If your policy has no alarm condition, the practical position is simple: a DIY alarm is a security choice, not an insurance one. If your policy does have a condition naming an approved installer, then a DIY system will not meet it, and you would need an NSI- or SSAIB-approved installation to comply. The way to be certain which situation applies is to read the policy and, if in doubt, ask the insurer.
Keeping an approved alarm valid for cover
If you do have an approved alarm tied to your policy, the certificate alone is not the end of the story. Insurers that require an approved system almost always expect it to be kept under a maintenance contract, serviced at the recommended intervals, and set when the home is unoccupied. An approved alarm that has been allowed to lapse — no live maintenance contract, faults left unrepaired — may no longer satisfy the condition.
Sensible record-keeping makes this easier to demonstrate. Keep the installation certificate, the maintenance contract and the service visit reports together, so that if a claim is ever made you can show the alarm met the approved-installer condition and was properly maintained.
It also helps to know what the approval actually certifies. NSI and SSAIB assess installers against the British and European intruder-alarm standards — the BS EN 50131 series — and against installation codes of practice, then audit them periodically to keep approval current. An installer can also grade a system (broadly, the higher the grade, the more determined the intruder it is designed to resist), and an insurer covering valuables may specify a minimum grade. This is why the certificate, not the brand of equipment, is what an insurer relies on: it ties your specific installation to a recognised standard and a vetted company. Because requirements and the standards behind them are updated over time, and insurers word their conditions differently, anyone unsure whether their system qualifies should confirm the position with their installer and insurer rather than assume an older certificate still suffices.
If you are moving from a self-fitted system to an approved one specifically to satisfy a condition, it is sensible to agree the requirement with the insurer first, then commission the work. Ask which standard and, if relevant, which alarm grade they expect, and whether the maintenance contract must be with the same approved company that installs the system. Getting this confirmed in writing before any money is spent avoids the frustrating outcome of paying for a professional installation that still falls short of the policy wording — for example, an approved install with no ongoing maintenance contract, when the condition required both. The certificate proves the standard at installation; it is the continuing contract and service record that prove the standard has been kept.
Frequently asked questions
Is an NSI or SSAIB alarm a legal requirement?
No. There is no law requiring an approved alarm. Approval is a quality standard for installers. Whether you need one is decided by your insurer and policy, and many homes are insured with no alarm at all.
Will insurers accept either NSI or SSAIB?
Generally yes. Both are recognised UK certification bodies for security installers, and most insurers that require an approved alarm accept a system installed and maintained by a company approved by either body. Confirm with your insurer if unsure.
Can I keep a DIY alarm if my policy doesn't mention one?
Yes. If your policy has no alarm condition, a DIY or self-monitored alarm is fine as a security measure. It simply earns little or no insurance credit and would not satisfy a condition that names an approved installer.
Sources & further reading
- National Security Inspectorate (NSI) — about approval
- Security Systems and Alarms Inspection Board (SSAIB)
- 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.