Holiday Let Smoke Alarm and CO Alarm Requirements UK

A single smoke alarm in the hallway does not meet UK fire safety requirements for a holiday let. Right, let's be straight about this: the alarm standards for paying guest accommodation are higher than those for your own home or a standard long-term tenancy — and there's a very good reason for that. Your guests are asleep in an unfamiliar building, often at odd hours, with no idea where the exits are. If a fire starts at 2am, they need to be woken up fast. Here's exactly what the law requires for smoke and CO alarms in a UK holiday let in 2026. For broader fire safety requirements, see our complete holiday let fire risk assessment guide.

The Legal Framework

Two pieces of legislation set the rules here:

• The Smoke and Carbon Monoxide Alarm (England) Regulations 2015 (as amended 2022) — requires a smoke alarm on every storey of a dwelling and a CO alarm in rooms with solid fuel appliances.
• The Regulatory Reform (Fire Safety) Order 2005 (RRO 2005) — requires the responsible person for paying guest accommodation to maintain adequate fire detection and warning. The government's own guidance ("Making your small paying guest accommodation safe from fire," January 2025) sets out what "adequate" actually means in practice.

Here's what you actually need to know: the 2015 Regulations are a floor, not a ceiling. The government's guidance for paying guest accommodation requires significantly more than the bare domestic minimum. Don't let anyone tell you a couple of battery alarms covers it.

Smoke Alarms: Required Grade and Coverage

Grade required: D1 — that means mains-powered with a tamper-proof battery backup. Battery-only alarms (Grade F1 or F2) are not compliant for holiday lets in regular use. The government's guidance is explicit: Grade F2 (disposable battery, non-interlinked) is not sufficient for paying guest accommodation. Grade F1 (sealed long-life battery) may be acceptable as a short-term stopgap only — not a permanent solution.

Coverage required:

• Every storey of the property
• Every guest bedroom — this is the critical requirement most hosts miss
• Hallways, landings, and main living areas
• Lounges and dining rooms

That bedroom requirement is the one that trips people up. A fire starting in a ground-floor kitchen needs to wake guests sleeping two floors up — before smoke reaches them. That means detection in the bedrooms themselves, not just the hallway outside.

Heat Alarms: Kitchen and Utility Rooms

The kitchen must have a heat alarm, not a smoke alarm. This is genuinely important — don't skip this bit. Smoke alarms in kitchens produce constant false alarms from cooking, which means guests disable or remove the batteries, leaving the property completely unprotected. A heat alarm (BS 5446-2 rated) detects the heat of a real fire without false-tripping from toast or steam. Heat alarms are also required in utility rooms and laundry areas.

Interlink: The Requirement Most Hosts Miss

All smoke, heat, and CO alarms must be interlinked — either hardwired or via wireless radio frequency. When one alarm activates, every alarm in the property must sound simultaneously. This is not optional. The government's guidance is clear: a standalone alarm detecting a fire in the kitchen will not wake guests asleep in an upstairs bedroom with the door closed. Interlink is what makes the system work as a system.

Modern mains-powered (Grade D1) alarms from most major manufacturers support wireless interlink as standard. Replacing a standalone system with an interlinked one typically costs £150–£400 depending on the size of your property.

Carbon Monoxide Alarms: What Is Required

Since 1 October 2022, the Smoke and CO Alarm (Amendment) Regulations 2022 require a CO alarm in every room containing a fixed combustion appliance. For holiday lets, that means:

• Every room with a gas boiler or gas fire
• Every room with a wood-burning stove or log burner
• Every room with an open fireplace
• Every room with an oil-fired heater or AGA
• Every room with an LPG appliance

Gas cookers are specifically exempt, but every other fixed combustion appliance requires a CO alarm in the same room. If a room has no fixed combustion appliance, no CO alarm is required there. Simple enough — but check every room.

Testing Requirements for Holiday Lets

Unlike long-term tenancies, holiday let alarms should be tested at every changeover — before each new guest arrival. That's what the government's guidance requires for paying guest accommodation. The simplest way to stay on top of it is a pre-arrival checklist that includes an alarm test. Note the date each time. If a fire inspector ever asks, that log is your evidence of compliance.

Document Compliance in Your Fire Risk Assessment

Our self-catering fire safety checklist covers alarms alongside all your other host obligations. FRASafe's holiday let fire risk assessment asks about alarm grade, coverage, interlink status, CO alarm placement, and testing frequency — generating a written record of compliance you can show to a fire inspector, your insurer, or the England STL (Short-Term Let) registration scheme from April 2026. If you host on Airbnb or similar platforms, see also our guide to Airbnb fire safety requirements in the UK. Assessments start at £45.