Legally required — annually

Gas Safety Certificate (CP12) for London Landlords

Annual CP12 inspections by Gas Safe registered engineers. Digital certificate issued within 24 hours. Serving London and a 120-mile radius.

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A Gas Safety Certificate — formally known as a CP12 — is the document issued by a Gas Safe registered engineer confirming that all gas appliances, pipework, and flues in a rental property have been inspected and found safe. Under the Gas Safety (Installation and Use) Regulations 1998 (SI 1998/2451), every UK landlord who lets a property containing gas appliances is legally required to have a gas safety check carried out every 12 months by a Gas Safe registered engineer. The certificate must be provided to existing tenants within 28 days of completion and to any new tenant before they move in. These obligations apply to all residential lets — houses, flats, HMOs, and short-let properties — regardless of tenancy type or length.

What's Checked During a CP12 Inspection

Gas tightness — pressure test across all connections and pipework to confirm there are no leaks

Appliance combustion performance — burner pressure, heat input, flue gas analysis, and CO/CO₂ ratios checked against safe limits

Flue integrity and condition — ensuring combustion gases are fully and safely discharged from the property

Ventilation adequacy — confirming air supply meets requirements for each appliance to operate safely

Safety device function — flame failure devices, thermostats, pressure relief valves, and overheat cut-outs tested

Pipework condition — visual inspection for corrosion, mechanical damage, inadequate support, and proximity to other services

Appliance servicing recommendations — the engineer notes any work outside the safety check scope that may be needed

Legal Requirements at a Glance

RequirementDetail
Renewal frequencyEvery 12 months. Can be carried out up to 2 months early without moving the anniversary date.
Tenant notificationWithin 28 days of the inspection being completed.
New tenantsBefore moving in. Electronic copies permitted if the tenant agrees.
Issued byGas Safe registered engineer only.
Penalties for non-complianceCriminal offence under the Health and Safety at Work Act 1974 — unlimited fine and/or up to 2 years' imprisonment on indictment. Failure to provide a valid CP12 to a tenant can also invalidate a section 21 (no-fault) eviction notice.
Record retentionMinimum 2 years.
Legal basisGas Safety (Installation and Use) Regulations 1998 (SI 1998/2451)

Source: HSE — Gas safety record keeping for landlords · gov.uk — Landlord responsibilities

Who Needs a CP12

Buy-to-Let Landlords

Any residential property let on an AST that contains gas appliances — boiler, gas hob, gas fire — requires an annual CP12.

HMO Operators

Houses in multiple occupation require a CP12 covering all gas appliances provided by the landlord in the property.

Airbnb & Short-Let Hosts

The Regulations apply to all letting arrangements regardless of tenancy length. Short-let and holiday-let properties with gas appliances must hold a valid CP12.

Property Managers

Managing agents acting on behalf of landlords share responsibility for ensuring annual gas safety checks are completed and records issued to tenants.

How Mainteniq Delivers Your CP12

1

Book via WhatsApp or phone

Choose a date that suits you or your tenant. We work around tenancy schedules and can often accommodate next-day appointments.

2

Gas Safe registered engineer attends

All checks carried out to HSE standards — gas tightness, combustion performance, flue integrity, ventilation, safety devices, and pipework.

3

Digital certificate within 24 hours

Your CP12 is issued digitally and ready to send to tenants — same day in most cases, next morning for end-of-day appointments.

4

Annual renewal reminder

We log your CP12 anniversary date and contact you before it expires — no missed renewals, no compliance gaps.

Gas Safe Register & Our Approach

All gas safety inspections coordinated by Mainteniq are carried out by Gas Safe registered engineers — the only engineers legally permitted to carry out gas work on domestic, commercial, and industrial appliances in Great Britain. You can verify any engineer's registration via the Gas Safe Register before they attend your property.

Mainteniq acts as a single point of contact and coordination layer for London landlords — we schedule your CP12 inspection, manage your compliance calendar, handle certificate delivery, and send renewal reminders before your anniversary date falls due. Gas work is carried out by vetted, Gas Safe registered engineers we work with directly.

HSE — Landlord gas safety responsibilitiesgov.uk — Landlord responsibilitiesGas Safe Register

Book Your CP12 Inspection Today

Serving London landlords across all 32 boroughs and a 120-mile radius. Digital certificate within 24 hours. Annual renewal reminders included.

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Also need EICR, PAT testing, or TM44? View all compliance certificates →

CP12 Gas Safety Certificate FAQs

Every 12 months. The Gas Safety (Installation and Use) Regulations 1998 require landlords to have a gas safety check carried out at least once in every 12-month period by a Gas Safe registered engineer. Since a 2018 amendment to the Regulations, the check can be carried out up to two months before the anniversary date without moving the deadline forward — meaning the annual cycle does not drift if you book slightly early. The resulting CP12 must be retained for at least two years and provided to tenants as required.

If your CP12 expires without a replacement check, you are in breach of the Gas Safety (Installation and Use) Regulations 1998 — a criminal offence under the Health and Safety at Work Act 1974. Two practical consequences apply immediately. First, you cannot lawfully serve a valid section 21 no-fault eviction notice until compliance is restored and the new certificate has been provided to the tenant. Second, if a gas-related incident occurs during a period without a valid certificate, your exposure to prosecution is significantly increased. Book a replacement inspection as soon as possible and deliver the new CP12 to your tenant within 28 days of the inspection being completed.

In most cases yes, subject to engineer availability. Mainteniq coordinates Gas Safe registered engineers across London and can typically arrange a CP12 inspection within 24 to 48 hours, with the digital certificate issued the same day or the following morning. For urgent situations — for example, where a CP12 expiry is blocking a new tenancy start or a section 21 notice — call us directly for fastest allocation.

Yes. The Gas Safety (Installation and Use) Regulations 1998 apply to all types of residential letting, including short-lets, serviced accommodation, and Airbnb-style holiday lets. The obligation is triggered by the act of letting the property to paying guests, not by the length or type of tenancy. Any property you let that contains gas appliances must have a valid CP12, and a copy should be provided to guests before they occupy the property — for short stays, this is typically displayed in the property or included in a welcome pack.

A minimum of two years from the date of inspection. The Gas Safety (Installation and Use) Regulations 1998 require landlords to retain gas safety check records for at least two years. If you use the early-renewal flexibility introduced by the 2018 amendment — carrying out the check up to two months before the anniversary — the HSE guidance recommends retaining the previous record until two subsequent annual checks have been completed. Mainteniq stores digital copies of all certificates we coordinate and makes them available to you on request.