Most of what this newsletter covers costs real money to get right. EPC upgrades run to thousands. EICRs and gas checks are annual and five-yearly costs. Licensing fees stack per property.

Smoke and CO alarms are different. Full compliance for a typical property costs less than £100 in hardware — and the fine for getting it wrong is up to £5,000 per breach. No other landlord obligation has a worse ratio between the cost of compliance and the cost of failure.

Yet alarm breaches remain one of the most common findings in council spot checks. This edition covers exactly what the rules require, the first-day-of-tenancy obligation most landlords don't know is theirs, who's responsible for what during the tenancy, and how alarm compliance now feeds into the bigger 2026 enforcement picture.

The obligations come from the Smoke and Carbon Monoxide Alarm (England) Regulations 2015, significantly expanded by the 2022 amendment. Plaza Estates

Smoke alarms:

At least one smoke alarm on every storey that has a room used wholly or partly as living accommodation. A two-storey house needs a minimum of two. A flat on one level needs at least one. Landings and hallways on a storey with living rooms count as needing coverage.

Carbon monoxide alarms:

A carbon monoxide alarm in any room with a fixed combustion appliance — excluding gas cookers. Carbon monoxide requirements include gas boilers and oil-fired systems, not just solid fuel burners. LetSafe UK

The 2022 amendment is the part that caught landlords out. Before October 2022, CO alarms were only required for solid fuel appliances — wood burners and coal fires. The 2022 amendment came into force on 1 October 2022 and significantly expanded the carbon monoxide alarm obligation to cover gas boilers and oil-fired systems. A property with a gas boiler in the kitchen needs a CO alarm in that room. Full stop. My WordPress

What doesn't need a CO alarm:

Electric heaters, electric cookers, and electric boilers do not produce carbon monoxide and do not require a CO alarm. And the specific exclusion that surprises people — gas cookers are specifically excluded from the requirement for a CO alarm under these regulations. A kitchen with only a gas hob and no boiler doesn't legally require one — though fitting one anyway is cheap and sensible. My WordPressLetSafe UK

Landlords must test alarms on the day a new tenancy starts. LetSafe UK

Not the week before. Not at the viewing. On the first day of the tenancy. This is a specific legal obligation that belongs to the landlord — and it's the compliance point that council enforcement and tenant claims most often turn on, because it's the one that's rarely documented.

The practical fix is simple: build the alarm test into your check-in process. Using a comprehensive Inventory and Schedule of Condition at the start of the tenancy is an excellent way to prove compliance, as both parties sign to confirm the alarms were tested and operational. A dated, signed inventory line — "all smoke and CO alarms tested and working in tenant's presence" — is your evidence for the life of the tenancy. LetSafe UK

The landlord should show the tenant how to test the alarms at the start of the tenancy so that they can regularly test alarms during the tenancy. Two minutes at check-in, documented, and the obligation is discharged and provable. Tenant Rights UK

This is where the split matters:

The landlord: must ensure alarms are working at the start of a tenancy. Once a fault is reported — it is the private landlord's responsibility to replace or arrange the repair of faulty alarms. Garrett WhitelockTenant Rights UK

The tenant: is responsible for testing the alarms regularly — recommended monthly — and reporting any faults to the landlord. Routine battery replacement during the tenancy typically falls to the tenant too, unless otherwise agreed. Remedy LegalGarrett Whitelock

The trigger point is the report. Before a fault is reported, the tenant tests and maintains. The moment they report a fault, responsibility transfers to you — and the clock on "reasonable time" starts running. A reported dead alarm that sits unfixed for weeks is exactly the kind of evidence that feeds a Fitness for Human Habitation claim.

One nuance worth knowing: your tenant does not have to give you access to check the alarms. While you must check that the smoke alarms are working correctly at the start of your tenancy, you are not required to test or replace the batteries during the tenancy. However, if you wish to check the alarms, and the tenant refuses access, protect yourself by keeping a record of your correspondence. Remedy Legal

The local authority performs spot checks to verify whether landlords for privately rented properties meet the smoke and carbon monoxide alarm regulations. If a rental property does not have alarms fitted, the local authority issues a remedial notice that gives the landlord 28 days to rectify the issue. If corrective action is not completed within 28 days, the landlord could be issued a fine of up to £5,000. Tenant Rights UK

If you still don't comply, the local authority can arrange for alarms to be fitted and fine you up to £5,000. Remedy Legal

Note the structure: the remedial notice comes first, with a 28-day window. The £5,000 fine is for landlords who ignore the notice. This is one of the more forgiving enforcement frameworks — which makes being fined under it particularly hard to defend as anything other than neglect.

Fines can be applied per property, potentially leading to significant costs for portfolio landlords. LetSafe UK

On its own, a missing smoke alarm is a £5,000 risk with a 28-day warning period. In the 2026 framework, it's more than that.

A poor safety record weakens your position in any possession claim. With Section 21 abolished under the Renters' Rights Act 2025, landlords increasingly rely on Section 8 grounds, where clear evidence of full compliance carries real weight. LetSafe UK

Missing alarms also feed directly into the Fitness for Human Habitation framework we covered in Edition 20 — fire is one of the assessed hazards, and inadequate fire detection is exactly the kind of defect that supports a tenant claim. And when the PRS Database opens for registration later this year, safety compliance records are the kind of evidence you'll want organised and current.

The pattern across every edition this year is the same: individual obligations that used to stand alone now interlock. An unfixed alarm isn't just an alarm problem — it's evidence in a fitness claim, a weakness in a possession case, and a record on a database.

The regulations don't mandate specific alarm types, but the practical guidance is clear:

Both battery-operated and mains-wired CO alarms with battery backup are compliant. Mains-wired alarms with sealed battery backup are the most reliable installation for the landlord's long-term obligations. My WordPress

For CO alarms, industry best practice is electrochemical CO sensors, which are more accurate and reliable. For any alarm — it's recommended to use alarms that meet the latest British Standards. My WordPressRemedy Legal

Sealed long-life battery alarms — the ten-year sealed units — remove the flat-battery problem entirely for roughly £15-25 per unit. Across a whole property that's under £100 for hardware that discharges a £5,000-per-breach obligation for a decade.

✅ One smoke alarm minimum per storey — every storey with living accommodation, including converted lofts.

✅ CO alarm in every room with a fixed combustion appliance — gas boilers, oil boilers, wood burners, gas fires, open fireplaces in use. Gas cookers excluded.

✅ Test every alarm on day one of every new tenancy — and document it on the signed inventory. This is your obligation, not the tenant's.

✅ Show the tenant how to test at check-in — monthly testing during the tenancy is then theirs.

✅ Fix reported faults promptly — responsibility transfers to you the moment a fault is reported. Keep the report and your response dated.

✅ If a tenant refuses access for checks — record the correspondence. The paper trail is your protection.

✅ Consider sealed ten-year units — removes the battery question for a decade at £15-25 per alarm.

✅ Check existing tenancies now — the rules apply to all tenancies, not just new ones. A property that pre-dates 2022 still needs CO alarms by every gas boiler today.

There is no cheaper compliance win in landlording. A morning's work and less than £100 in hardware covers a typical property completely — against a £5,000-per-breach fine, a weakened possession position, and a gift-wrapped piece of evidence for any tenant claim.

The landlords who get caught on alarms aren't unlucky. They're landlords who never built the day-one test into their check-in process, never documented anything, and found out what that documentation was worth only when they needed it.

Test on day one. Write it down. Fix faults fast. That's the entire obligation.

Track alarm installations, day-one test dates and fault reports alongside every certificate and compliance record across your portfolio.

£19 one-time, instant access 👉 uklandlordproperty.gumroad.com/l/oahbhl

Also on Etsy 👉 tlbtemplates.etsy.com

Coming up next edition — The PRS Ombudsman: what it is, when it launches and what landlords need to do.

The Landlords Brief is published for UK landlords. Subscribe free at thelandlordsbrief.co.uk. This newsletter is for general information only and does not constitute legal or financial advice.