CP12 gas safety certificate: cost and rules (2026)

What is a CP12 gas safety certificate?

A CP12 (Landlord Gas Safety Record) is the legal document proving a rented property's gas appliances, flues and pipework were checked as safe by a Gas Safe registered engineer. Landlords must renew it every 12 months, give tenants a copy within 28 days, and keep records for two years. It typically costs £60–£120 in 2026.

"CP12" is just the everyday name for the Landlord Gas Safety Record. The "CP" stands for the old CORGI form number, and the name stuck even after Gas Safe replaced CORGI in 2009. Whatever it's called, the document confirms that every gas appliance, flue and length of associated pipework in the property was inspected and found safe.

Only a Gas Safe registered engineer can carry out the check and issue the record. The requirement comes from the Gas Safety (Installation and Use) Regulations 1998, and it applies to anyone letting a property with gas appliances, flues or pipework — from a single buy-to-let to a large portfolio.

A CP12 is not the same as a boiler service

This trips a lot of landlords up. A CP12 is a safety inspection: it checks that appliances are burning correctly, that flues are clearing combustion gases safely, and that there are no dangerous faults. A boiler service is preventative maintenance — cleaning components and keeping the boiler running efficiently. The two overlap, and many engineers will do both in one visit, but the CP12 is the one the law requires you to hold every year.

Key facts

The quick version, before the detail.

• Legal name: Landlord Gas Safety Record (commonly called a "CP12").
• Required every 12 months under the Gas Safety (Installation and Use) Regulations 1998.
• Must be issued by a Gas Safe registered engineer.
• Give tenants a copy within 28 days of the check; keep records for two years.
• Typical 2026 market cost: £60–£120, depending on the number of appliances and the region.
• Failed appliances are marked AR (At Risk) or ID (Immediately Dangerous) — they must be repaired before they're used again.

How much does a CP12 cost in 2026?

A CP12 typically costs £60–£90 for a single gas appliance in 2026, with a broader range of £50–£120 once you factor in location and the number of appliances. The figures below are typical UK market prices — they are not Smart Plan's, and Smart Plan does not issue CP12 certificates. Always get a written quote from your engineer before booking.

Typical CP12 cost by property

Because a gas safety check and a boiler service cover different ground, booking them together on one visit is usually the cheapest way to stay both legal and well-maintained — many engineers price the pair at £20–£40 less than two separate call-outs. Again, these are market figures to help you budget, not a price Smart Plan sets or charges.

The rules landlords must follow

The core duties are set out by the Health and Safety Executive (HSE) and on gov.uk, and they're simpler than they first look. Miss any of them, though, and you're in breach of the 1998 Regulations — so it's worth knowing them cold.

• Have every gas appliance and flue checked for safety at least every 12 months.
• Use a Gas Safe registered engineer — only they can legally carry out the check and issue the record.
• Give existing tenants a copy of the record within 28 days of the check being done.
• Give any new tenant a copy before they move in.
• Keep copies of each record until two further checks have been carried out — a minimum of two years.
• Give tenants reasonable notice (at least 24 hours) when you need access to carry out the check.

What happens if the property fails the gas safety check?

If an appliance isn't safe, the engineer records it as either At Risk (AR) or Immediately Dangerous (ID) under the Gas Industry Unsafe Situations Procedure (GIUSP). At Risk means there's a fault that could become dangerous. Immediately Dangerous means it's a danger to life or property right now.

With your permission, the engineer will turn off or disconnect an Immediately Dangerous appliance and label it so it isn't used. That appliance then stays off until it's been repaired and re-checked. As the landlord, arranging that repair before the appliance is used again is your responsibility — a failed check doesn't pause your duty to keep the property's gas safe.

The CP12 still records the outcome, including any unsafe situation found and the action taken. Once the fault is fixed and the appliance passes a fresh check, you'll have a clean record again.

If you ever smell gas or suspect carbon monoxide

This is the one thing that can't wait. If you or a tenant smell gas, or a carbon monoxide alarm sounds, call the National Gas Emergency Service on 0800 111 999 straight away, open windows, turn the gas off at the meter, avoid using electrical switches, and get everyone out. A dangerous appliance is always a job for a Gas Safe registered engineer — never attempt a gas repair yourself.

How often do you need a CP12, and what's the penalty for not having one?

You need a valid gas safety check every 12 months — once a year, on every gas appliance and flue in the property. Helpfully, you can have the check done up to two months before the current record expires without losing your original anniversary date, so you can stay ahead of the deadline without shortening your renewal cycle. That's the simplest way to avoid an accidental lapse.

The penalty for getting it wrong is serious. Failing to comply with the Gas Safety (Installation and Use) Regulations 1998 is a criminal offence, enforced by the HSE. It can lead to prosecution, fines and, in serious cases, imprisonment — quite apart from the risk to your tenants and the trouble it can cause with your own insurers and letting agents.

CP12 vs boiler service vs a cover plan

These three get muddled, but they do different jobs and they're complementary, not substitutes. A CP12 proves your gas is safe. A boiler service keeps it running well. A cover plan spreads the cost of repairs when something does go wrong — within limits it's worth reading before you buy.

Three different things a landlord might need

Smart Plan is a service plan, not insurance. Cover is modular — you build your own plan from separate modules and pay only for the ones you pick, so a landlord who just wants the boiler covered isn't paying for anything else. You pay monthly, but that doesn't mean you can leave whenever you like: the plan runs month to month only until you make your first claim. Once you use a service, you're committed to a 12-month agreement period, with a 75% charge on the remaining months if you leave early — and a homeowner who joins to fix a broken boiler will use a service almost straight away, so for most buyers that monthly freedom ends on the first repair. There's a 14-day cooling-off period, but it ends the moment you use a service.

Cover pays for parts and labour, but it's capped — and for older boilers the cap is much lower, which matters because older boilers tend to cost more to repair. For boiler and central heating cover the limit is up to £200 a year once the boiler is seven years or older, against up to £500 a year while it's under seven. If your boiler is ageing, that £200 ceiling is the single number to check first. Appliance cover is capped at £225 and other modules at £500.

A £95 call-out fee applies to certain call-outs, charged per visit, so a covered repair can still cost you £95 on the day — the terms set out exactly which call-outs it applies to, so check them before you rely on the plan for a specific job. Call-outs run Monday to Friday, 08:00–18:00. Outside those hours only a genuine emergency breakdown is attended, and Smart Plan decides what counts as an emergency, so evening and weekend cover for a non-emergency fault is limited — worth weighing if you're a landlord with a tenant and a legal repair duty. When a covered fault is attended, a Gas Safe registered engineer from a national network of vetted engineers comes out to fix it.

A cover plan doesn't replace your CP12 — you still need the annual safety check by law — but it does spread the cost of a repair, up to your cover limit, when an appliance fails between checks. Smart Plan is from UK Boiler Company Ltd, trading since 2014, and has looked after over 15,000 customers.

CP12 gas safety certificate FAQs

Renting out a property with a boiler? Spread the repair costs.

A CP12 keeps you legal; a Smart Plan boiler module spreads the cost of covered repairs when something breaks. It's a service plan, not insurance — you build your own cover and pay only for the modules you pick. Parts and labour are included up to your cover limit: up to £500 a year for a boiler under seven years, but only up to £200 once it's older. A £95 call-out fee applies in defined cases, and call-outs run Monday to Friday, 08:00–18:00 unless it's a genuine emergency breakdown.

Related links

• Landlord boiler cover
• Gas safety: a landlord's responsibilities
• Boiler fault to fix first? Book a repair
• Boiler & central heating cover
• HSE — gas safety for landlords and tenants
• gov.uk — gas safety in let properties
• Gas Safe Register — if an appliance is unsafe