Gas Safety Certificates for Landlords: The CP12 Rules, Deadlines, and Penalties

Every landlord with gas appliances must carry out an annual CP12 check. Missing it is a criminal offence — not a civil fine. Here are the rules, the 8-week early-booking window, and what prosecution actually means.

Gas safety is the one landlord obligation where the word "fine" does not capture the risk. The Gas Safety (Installation and Use) Regulations 1998 make failure to carry out an annual check a criminal offence under the Health and Safety at Work etc. Act 1974 — with prosecutions by the Health and Safety Executive, unlimited fines, and custodial sentences on the table. The compliance mechanics have not changed since 1998; what has changed is the cost of getting them wrong.

What the law requires

Regulation 36 of the Gas Safety (Installation and Use) Regulations 1998 sets out four distinct duties for landlords of residential rental properties:

Annual inspection. Every gas appliance and flue the landlord owns and provides for the use of tenants must be checked by a Gas Safe registered engineer at intervals of no more than 12 months. The check covers the appliance, its pipework, and any associated flue or chimney.

Record keeping. The Gas Safety Record — universally called the CP12 — must be retained for at least two years from the date of the inspection.

Tenant notification. Existing tenants must receive a copy within 28 days of the check. New tenants must receive a copy before they move in — not within 28 days, immediately on move-in day.

Ongoing maintenance. A valid CP12 does not discharge the continuing maintenance duty. A tenant report of a gas smell or fault triggers same-day action regardless of when the last check was carried out.

What is — and is not — covered

The obligation covers gas appliances and flues the landlord owns and provides. A tenant's own gas cooker is outside the scope of the annual check duty. All landlord-supplied fixed gas appliances — boilers, gas fires, gas hobs if landlord-provided — are within it.

The 8-week early-booking window

The most misunderstood part of the Regulations is the 2018 amendment that allows early booking without resetting the anniversary date. You can arrange the annual check up to 8 weeks before the current certificate expires, and the next renewal will still fall on the same date as before. Book any earlier and the anniversary moves forward to the new inspection date.

In practice: if your certificate expires on 15 March, you can have the check done any time after 19 January and the next renewal will still be 15 March the following year. Use this window — do not leave booking until the week before expiry.

The penalty regime

Non-compliance with the Gas Safety Regulations is a criminal offence under s.33 of the Health and Safety at Work etc. Act 1974. This sets it apart from EICR and EPC obligations, where the enforcement route is civil penalty.

Prosecutions are brought by the HSE or, in some cases, local authorities:

Summary conviction (Magistrates' Court): unlimited fine and/or up to 6 months' imprisonment
On indictment (Crown Court, serious harm or death): up to 2 years' imprisonment

The HSE publishes all convictions on its enforcement notices database. A 2024 custodial sentence is already on the record.

Separately, local authorities can issue a civil penalty of up to £30,000 per offence as an alternative to prosecution — a route councils prefer because it avoids the courts.

Secondary consequences

A lapsed CP12 also creates problems outside formal enforcement:

Insurance refusal. Standard buy-to-let policy conditions require a valid gas safety certificate. Insurers can refuse claims — including claims entirely unrelated to gas — if the CP12 has lapsed.
Deposit dispute outcomes. TDS and DPS adjudicators check compliance during end-of-tenancy disputes. A missing CP12 swings borderline decisions toward the tenant.
Awaab's Law (October 2026). The private rented sector extension of Awaab's Law introduces statutory repair clocks for hazards. Gas-related hazards sit inside that framework.

Access and the three-attempt rule

If a tenant refuses access for the annual check, maintaining a documented record of three separate access attempts is the accepted basis for a defence. Letters (with proof of postage), emails with read receipts, or a note through the door each count. Three undocumented phone calls do not.

Properties with no gas supply

If the property has no gas supply and no gas appliances, there is no CP12 requirement. Confirm this in writing to the tenant at the start of the tenancy.

Managing CP12 across a portfolio

Certificate expiry dates fall at different times across a portfolio. mypy's certificate tracking monitors CP12 expiry dates across every property and sends reminders at 60, 30, and 14 days before the certificate is due — so renewals are scheduled in advance rather than caught late. Free for up to 2 properties.

Frequently asked questions

Does the CP12 requirement still apply now that Section 21 is abolished?

Yes. Under the old regime, an invalid CP12 could block a Section 21 notice. Section 21 is now abolished, but the criminal duty under the Gas Safety Regulations is entirely unchanged. Enforcement has moved to local authority civil penalties and HSE prosecution rather than being embedded in possession proceedings.

Can the tenant carry out the annual check themselves?

No. The check must be carried out by a Gas Safe registered engineer. Verify any engineer's registration on the Gas Safe website before the appointment.

Is a gas safety check the same as a boiler service?

No. A boiler service is a maintenance activity. A gas safety check is a legal compliance inspection resulting in a certificate. Many engineers combine both in a single visit, but the CP12 records the legal check — a boiler service alone does not satisfy the Regulations.

We have a communal boiler in an HMO. Who is responsible?

The landlord. The obligation follows ownership — if the landlord owns and provides the appliance, the annual check and CP12 duty sit with the landlord, whether the boiler serves an individual flat or a communal area.

How long do I keep old CP12 certificates?

The Regulations require retention for a minimum of two years. For portfolio operators, HSE recommends keeping records beyond the minimum. Store them digitally against the property address, organised by date.

Sources

This article is general guidance, not legal advice. Verify your obligations against current GOV.UK guidance or seek professional advice for your circumstances. Last reviewed 2026-07-06.