Which certificates are required by UK law?

Mandatory certificates for all properties

CO alarm — when it's required

A carbon monoxide alarm is required in any room that contains a fixed combustion appliance (gas boiler, gas fire, solid fuel stove, oil boiler). Since 1 October 2022, this includes gas boilers — not just solid fuel appliances.

HMO licence

Properties with 5 or more occupants forming 2 or more households require a mandatory HMO licence from the local council. Some councils also operate additional or selective licensing schemes — check with your local authority.

How LetSense tracks this

Go to the Compliance tab on any property to see all certificate statuses. Red = expired, amber = expiring within your alert threshold, green = current. Automated reminders go out at 90, 60, and 30 days before expiry.