Gas Safety Certificate (CP12): The Landlord's Guide

If your rented property has any gas appliances, a flue or gas pipework, you have a legal duty to keep them safe and to have them checked every year. The document that proves it is the Gas Safety Certificate — still widely called a CP12. Of all the landlord certificates, this is the one with the shortest cycle and the least room for excuses — where its electrical counterpart, the EICR, comes round only every five years, the gas check is annual — so it's worth getting the routine right.

What is a CP12?

A CP12, officially a Landlord Gas Safety Record, is the record produced when a registered engineer inspects the gas appliances, flues and pipework you're responsible for in a let property. It confirms each appliance has been checked and states whether it is safe to use. "CP12" is an old form number that stuck — you'll see both terms used interchangeably, and they mean the same thing.

How often do landlords need one?

Gas appliances and flues must be checked at least every 12 months. To avoid the deadline creeping later each year, you're allowed to carry out the check up to two months before the current record expires without losing your original renewal date — the new certificate runs from the old expiry, not from the day the engineer visited. Use that window; it's the simplest way to stop the annual date drifting.

Who can issue one?

Only an engineer on the official Gas Safe Register may carry out the check and issue the record — the register replaced the old CORGI scheme. Every Gas Safe engineer carries an ID card showing the categories of work they're qualified for (boilers, cookers, fires and so on). It's reasonable to check the card and confirm the engineer is registered for the appliances in your property; you can verify a registration number on the Gas Safe Register website.

What does the check cover?

• Each gas appliance you provide — boiler, cooker, hob, gas fire.
• Flues and chimneys serving those appliances.
• The gas pipework and, where relevant, safety devices and ventilation.

Appliances the tenant owns and brought with them generally aren't your responsibility, though the connecting pipework and flue often still are. If an engineer finds something unsafe, it should be recorded, and a dangerous appliance may be turned off with the tenant's permission until it's fixed.

Giving the record to your tenants

Issuing the certificate isn't the end of it — you also have to hand it over. The rules require you to give a copy of the gas safety record to existing tenants within a set period (commonly cited as 28 days of the check) and to any new tenant before they move in. Keep proof you provided it. This matters beyond safety: a missed or unprovable gas record has always weakened a landlord's hand in possession proceedings, and with Section 21 now abolished and possession running through Section 8 grounds, a clean, provable paper trail matters more than ever — so a missed handover can cost you far more than the check itself.

What are the penalties?

Gas safety is enforced by the Health and Safety Executive, and the duties sit under health-and-safety law rather than the softer end of the compliance rulebook. Breaches can lead to enforcement action, unlimited fines on conviction and, in the most serious cases, imprisonment. Beyond the legal exposure, an out-of-date record complicates your insurance and, as above, your ability to regain possession. It's also one of the first documents a council wants when it asks for your compliance records, and a current gas certificate is set to be a prerequisite for registering each property on the landlord register now in testing. This is not a corner to cut.

What should landlords do?

1. Use a Gas Safe registered engineer and check they're registered for the appliances involved.
2. Book within the two-month window before expiry so your renewal date holds steady year after year.
3. Give tenants a copy — within the required period for existing tenants, and before move-in for new ones — and keep evidence you did.
4. Act on any defects straight away and keep records of the remedial work.
5. Store the record and its expiry date somewhere you can produce instantly, and set a reminder well ahead of the 12-month mark.

General guidance for UK landlords, not legal advice. Gas safety duties apply under the relevant regulations, chiefly in England, Wales and Scotland; exact requirements, timescales and penalties are set by government and can change — always verify current requirements at GOV.UK, confirm your engineer on the Gas Safe Register, and take professional advice where needed.