Gas Safety Certificate (CP12) in London

Gas Safety Certificate Overview

A landlord gas safety certificate is the record produced after a Gas Safe registered engineer checks the gas appliances, fittings and flues in a rented property. It is often still called a CP12, a name from an older form, while the official term is the Landlord Gas Safety Record.

The record lists each appliance checked, where it is, the results of the tests and any defects found, along with the engineer's details and the date. If something is unsafe, the record says so and notes what action was taken. Keep it with your tenancy documents, as you will need it for tenants and agents.

What the Inspection Covers

The check is about safety, not a full service. We test each gas appliance the landlord provides and the flues serving them, and look over the installation pipework.

• Boilers, gas fires, cookers and hobs checked for safe operation
• Flues and chimneys checked for correct routing and flow
• Ventilation checked against the appliance requirements
• Tightness test on the gas installation pipework
• Operating pressure or heat input measured, and safety devices tested

Where appliances belong to the tenant, the landlord is not required to check them, although we will still flag anything we see that looks unsafe.

Legal Requirements for Landlords

Under the Gas Safety (Installation and Use) Regulations 1998, landlords must have gas appliances and flues they provide checked at least once every 12 months by a Gas Safe registered engineer. A copy of the record goes to existing tenants within 28 days of the check, and to new tenants before they move in. Records must be kept for at least two years.

In England, the 2022 amendment to the smoke and carbon monoxide alarm regulations also requires a carbon monoxide alarm in any room used as living accommodation that contains a fixed combustion appliance, with gas cookers excluded. The alarm is a separate duty from the gas check, but we note whether one is present.

Gas Safe Registered Engineers

Only a Gas Safe registered engineer can carry out a landlord gas safety check, and their registration must cover the types of appliance being checked. Every check we carry out is done by a Gas Safe registered engineer, who carries an ID card you or your tenant can ask to see.

You can confirm any engineer's registration on the Gas Safe Register website by entering the licence number from their card. It is worth doing for any gas work at your property, and agents often keep a note of it with the certificate on file.

Certificate Validity and Renewal

A gas safety record covers 12 months. The rules allow the next check to be done up to two months before the current record runs out while keeping the original expiry date, so an early check does not shorten your year.

That window is useful for London lets where access can be awkward. Booking the next check inside the window, which gives time to arrange a second visit if a tenant is away or a fault needs putting right first. Letting the record lapse leaves the landlord in breach, even if the appliances are safe.

Gas Safety Certificate Cost

We give you a fixed price in writing before booking. The main factor is how many gas appliances the property has: a flat with a single combi costs less to check than a house with a boiler, gas fire and hob.

Access also plays a part, such as a boiler in a loft or several flats in one building booked on the same day. Many landlords combine the check with an annual boiler service, which is priced as one visit and saves booking the engineer twice. Any remedial work found is quoted separately, with parts listed, before we carry it out.

How Booking and Attendance Works

The landlord or the letting agent books the check and gives us the tenant's contact details. We then arrange a time directly with the tenant, or through the agent if you prefer. The tenant, or someone they nominate, needs to be home to let us in, and the engineer needs clear access to each appliance and the gas meter.

If a tenant does not give access after reasonable attempts, keep a record of each attempt. The regulations expect landlords to show they took all reasonable steps. The completed record is emailed to you or your agent once the check is finished.

Areas and Property Types Covered

We carry out gas safety checks throughout London on HMOs, purpose-built flats, mansion blocks, converted houses split into flats and single-family lets. In HMOs and conversions there can be several meters and boilers in one building, and we record each one clearly so the right tenant gets the right paperwork.

Portfolio landlords and agents can book several properties on the same run, which cuts the back-and-forth over access and keeps renewal dates in step.