CO Alarm (Carbon Monoxide Alarm)
Quick answer
Required from 1 October 2022 in every room with a fixed combustion appliance (excluding gas cookers) in private rented homes in England. The landlord must ensure an alarm is present and in working order at the start of each tenancy. Maximum civil penalty: £5,000 per property.
At a glance
- In force
- From 1 October 2022
- Where
- Every room with a fixed combustion appliance (excluding gas cookers)
- When
- Present and working at the start of each tenancy
- Max penalty
- £5,000 per property
Full guide
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Open full guideWhy CO Alarm (Carbon Monoxide Alarm) matters for landlords
The October 2022 expansion of the CO-alarm rules to all fixed combustion appliances (wood burners, oil boilers, solid-fuel fires) caught many landlords out because before then only gas-heater rooms needed an alarm. The civil penalty is issued by the local authority on a 28-day remedy timetable; a quick fix after tenant complaint usually avoids the £5,000 cap, but ignoring a remedial notice turns it into the full amount. Keeping a photo-stamped inventory at tenancy start is the cleanest audit trail.
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Official sources
LetCompliance editorial reviews this entry every quarter against the sources above. Always confirm specific duties with a qualified solicitor or your local council.
Related terms
Smoke Alarm
Mains-powered or sealed 10-year battery smoke alarms are required on every storey of a private rented home in England under the Smoke and Carbon Monoxide Alarm (England) Regulations 2015 (amended 2022). Landlords must test them at the start of every tenancy and replace faulty alarms once reported.
Capital Allowances
Tax relief for capital spending on qualifying "plant and machinery". For a standard residential letting they are generally NOT available — furniture and appliances are covered instead by Replacement of Domestic Items Relief. Capital allowances mainly apply to equipment in the communal areas of some HMOs and to commercial property; the furnished holiday let regime that allowed them was abolished from April 2025.
Capital Expenditure vs Revenue Expenditure
The line that decides whether a cost reduces your rental profit now or your Capital Gains Tax later. Revenue expenditure (repairs, maintenance, replacing like-for-like) is deducted from rental income in the year you spend it. Capital expenditure (improvements, extensions, first-time installation of something new) is added to the property’s cost base and only counts against CGT when you sell.
Capital Gains Tax (CGT)
Tax on the profit from selling a rental property. From April 2024 the CGT annual exempt amount was reduced to £3,000 and residential property gains are taxed at 18% (basic rate) or 24% (higher rate). A CGT return must be filed and tax paid within 60 days of completion.
Capital Growth
The increase in a property’s market value over time, as distinct from the rental income it produces. It is only realised (and taxed, via Capital Gains Tax) when the property is sold. Many landlords weigh capital growth against rental yield when choosing where and what to buy.
Check-in / Check-out Report
The dated, photographed inventory record taken at the start (check-in) and end (check-out) of a tenancy, signed by tenant and landlord/agent. It is the primary evidence base for any deposit deduction claim through the DPS, TDS or mydeposits adjudication process — without it, the scheme will almost always award the deposit back to the tenant. Best practice: third-party inventory clerk, time-stamped photographs of every room and meter reading, and tenant sign-off within 7 days.