If you let a property with any gas appliance, flue, or pipework, one piece of paperwork sits above everything else on your compliance list: the annual gas safety check. It's not optional, there's no grace period, and the consequences of letting it lapse are more serious than most landlords realise until it's too late.
What the law actually requires. Under the Gas Safety (Installation and Use) Regulations 1998, every gas appliance, flue, and length of pipework in a rental property must be inspected at intervals of no more than 12 months, by a Gas Safe registered engineer, nobody else is legally permitted to carry out the check. The resulting document, the Landlord Gas Safety Record, is what most people still call a CP12, a name that's stuck from the old CORGI reporting form even though CORGI was replaced by Gas Safe back in 2009.
The disclosure rules matter as much as the check itself. You must give existing tenants a copy of the current record within 28 days of the check, and new tenants must receive it before they move in. Records need to be kept for at least 2 years. If the property is an HMO, a copy also has to be displayed somewhere in a common area.
A scheduling detail most landlords don't know about. Since 2018, you're allowed to carry out the annual check up to 2 months before the current certificate expires, without losing the original expiry date. If your CP12 expires on 1 September, you can book the check any time from 1 July onward, and the new certificate still runs to 1 September the following year, not from whenever the engineer actually attended. This exists specifically so landlords aren't forced into an awkward, ever-earlier renewal date every year.
What happens if a certificate lapses. This is a criminal offence, not a civil one, prosecuted by the Health and Safety Executive under the Health and Safety at Work etc. Act 1974. A Magistrates' Court conviction carries fines of up to £20,000 and up to 6 months in prison. If the case is serious enough to go to the Crown Court, the maximum penalty is an unlimited fine and up to 2 years' imprisonment. Where a death has resulted from a gas safety failure, landlords have faced manslaughter charges. Separately, a tenant can apply to the First-tier Tribunal for a Rent Repayment Order of up to 12 months' rent if you're convicted of a relevant offence.
It matters for possession too. Since the Renters' Rights Act ended Section 21, every possession claim now runs through a Section 8 ground, and courts have discretion to weigh ongoing compliance failures when deciding whether to grant possession. A missing or lapsed gas safety record is exactly the kind of documentation gap that can undermine an otherwise straightforward case, at precisely the moment you need it to go smoothly.
In practice, the fix is simple. A calendar reminder, a trusted Gas Safe engineer, and treating the 2-month early-booking window as your actual deadline rather than the expiry date itself, that's the whole system. It's one of the areas where a missed date costs far more than the certificate itself ever would.