Your Landlord Gas Safety Certificate (CP12) Checklist

Keeping gas appliances safe is a key legal duty for any landlord, but the process does not have to be complicated. With a clear understanding of the landlord gas safety certificate (CP12), you can stay compliant, protect your tenants and avoid repeat visits.

What a landlord gas safety certificate (CP12) covers

A CP12 is the record a Gas Safe registered engineer leaves after carrying out an annual gas safety check at your rental property. It confirms that the gas appliances and installation have been checked for safety at that point in time.

The certificate is sometimes called a landlord gas safety record. It should include details of the engineer, the property, the appliances checked, the test results and any defects or safety concerns that need attention.

What the engineer will check during a CP12 visit

The exact checks depend on which gas appliances are installed and owned by you as the landlord. In most rental homes, the engineer will focus on a few key areas.

Your engineer will usually check:

• Gas boiler – basic safety checks on the boiler, its burner, seals and safety devices

• Gas hob or cooker – flame picture, ignition, stability and safety controls

• Gas fires (if fitted) – safe combustion, flame picture and appropriate ventilation

• Flues and chimneys – condition, route and whether fumes can escape safely outside

• Ventilation – air vents and grills are present and not blocked

• Gas pipework – a tightness test to check for leaks on the system

Appliances supplied by tenants themselves are the tenant’s responsibility, but your engineer will still check the landlord-owned pipework that feeds them. Always clarify which appliances you own before the visit.

How to prepare for a successful CP12 appointment

A bit of preparation can prevent failed visits, extra charges and frustration for both you and your tenants. It also helps the engineer complete the check efficiently.

As a landlord, it helps to:

• Ensure clear access to the boiler, gas meter, gas hob, gas fire and any flues or inspection hatches

• Ask tenants to tidy areas around appliances and keep pets secure during the visit

• Locate appliance manuals if you have them, especially for older or less common models

• Confirm contact details so the engineer or letting agent can reach the tenant on the day

Coordination with tenants is important. Give them reasonable notice, confirm the time window, and remind them that the visit is a legal safety check, not an optional convenience.

Landlord checklist for CP12 day

Before the engineer arrives, run through this quick checklist:

Property access: Keys available, any alarms or entry codes shared appropriately, and someone responsible able to attend if needed.

Appliance access: No furniture blocking boilers, cookers, gas fires or the gas meter, and loft hatches or airing cupboards are easy to reach.

Information ready: Previous gas safety records if you have them, any known issues noted, and the agreed list of landlord-owned appliances.

What the CP12 outcomes mean

At the end of the visit, the engineer will explain any findings and record them on the gas safety certificate. Not every outcome is a straightforward pass or fail, so it helps to understand the wording.

Pass / satisfactory: All checked appliances and pipework are considered safe at the time of inspection, with no immediate safety concerns recorded.

At risk (AR): The installation has a fault that could become dangerous if left uncorrected. The engineer will usually advise not to use the appliance until it is repaired, but it may not be disconnected immediately.

Immediately dangerous (ID): The appliance or installation is unsafe to use and must not be operated. The engineer is obliged to make it safe, which often means disconnecting it from the gas supply.

If issues are found, you are responsible for arranging remedial work with a Gas Safe registered engineer. A follow-up check may be needed to confirm that repairs have made the system safe.

Record keeping and giving tenants a copy

Landlords must keep a record of each gas safety check. Keep copies of CP12 certificates for at least two years, ideally in both digital and paper formats, so you can show compliance if asked.

Tenants should receive a copy of the latest CP12 within 28 days of the check, or before they move in if they are new tenants. You can provide this by email or as a printed copy, but make sure it is clear and legible.

It is also good practice to keep notes of any gas-related repairs between annual checks. This builds a complete picture of the property’s gas safety history and can be helpful if you change managing agents or engineers.

How often gas safety checks are needed

In most cases, a landlord gas safety check is required at least every 12 months on each property that has gas appliances or a gas supply. The certificate shows the date of the check, which forms the basis for the next deadline.

Some landlords plan their calendar so that the next check is completed a little early each year. This reduces the risk of slipping past the due date if there are access issues or busy seasonal periods.

Common questions about CP12 certificates

Is a boiler service the same as a CP12?

No. A CP12 is a safety check and legal record, while a boiler service is a more in-depth inspection and clean of the boiler to maintain performance and reliability. Many landlords choose to have both done together for convenience.

Do I need one certificate for each appliance?

You do not need separate CP12 certificates for each appliance. One gas safety record can list multiple appliances in the same property, as long as they have all been checked during the visit.

If you own a portfolio with several properties, each address needs its own valid gas safety record.

What if the tenant refuses access?

Landlords must take all reasonable steps to arrange gas safety checks, which includes giving proper notice, offering reasonable appointment times and keeping records of attempts made. If a tenant repeatedly refuses access, this can become a legal matter.

In that situation, you should seek advice from your letting agent, legal adviser or local authority. Document every attempt to access the property for the CP12, including letters, emails and messages.

Next steps for your landlord gas safety check

Planning your CP12 ahead of time helps keep your properties compliant and your tenants safe. Combine clear communication with tenants, good record keeping and a trusted Gas Safe registered engineer, and the process becomes routine rather than stressful.

If you are ready to arrange a landlord gas safety certificate or would like to pair your CP12 with a boiler service in the same visit, you can find more details on our gas safety certificate service page. To book an appointment, contact TWINSUN HEATING LTD on 01942669247.