How Much Does a CP12 Cost? Gas Safety Certificate Price Guide for UK Landlords (2026)

A CP12 gas safety certificate typically costs £45–£90 in most of the UK in 2026, rising to £70–£120 in London and the South East. Add roughly £10–£20 per extra gas appliance, and expect around £100–£160 if you combine the check with a boiler service.

Those are the headline numbers. The rest of this guide explains what you are actually paying for, why two landlords in the same town can be quoted very different prices, and where it is safe — and not safe — to economise.

Typical CP12 prices in 2026

Prices are set by the market, not by regulation, so there is no official fee. These ranges reflect what independent Gas Safe engineers and small firms commonly charge:

| Scenario | Typical price | | --- | --- | | Standard check, 1–2 appliances (most of the UK) | £45–£90 | | Standard check, 1–2 appliances (London and South East) | £70–£120 | | Each additional appliance | £10–£20 | | CP12 + boiler service in one visit | £100–£160 | | Short-notice or out-of-hours visit | add £20–£50 |

A "standard" rental property — a flat or house with a gas boiler and a gas hob — sits at the bottom of the range. A larger house with a boiler, hob, gas fire and a separate water heater sits nearer the top, simply because each appliance takes time to test.

If a quote is dramatically outside these ranges in either direction, ask why. Expensive is not automatically thorough, and cheap is not automatically a bargain — more on that below.

What you are actually paying for

A CP12 looks like a piece of paper, but the price buys an engineer's time and liability. During the visit — usually 30 to 60 minutes — the engineer tests every appliance and flue you provide: combustion performance, operating pressure, ventilation, flue operation, safety devices, and a tightness test at the meter to rule out leaks. If anything is wrong, they classify the fault, make it safe where necessary, and record the defect and action taken.

The engineer's Gas Safe registration is the other thing you are paying for. Only a registered engineer can legally carry out the check and issue the record, and their registration number goes on your certificate. That number carries their professional liability — which is exactly why you should verify it. Check the engineer's ID card, or look them up on the Gas Safe Register, before the visit. If you are unclear on what the document itself must contain, our CP12 explainer walks through it line by line.

What makes the price go up or down

Four factors explain most of the variation between quotes:

1. Number of appliances. Every appliance and flue you provide must be checked, and each one adds time. Tenant-owned appliances are excluded, but the pipework and flues serving them are not.
2. Location and travel. Engineer day rates are higher in London and the South East, and rural properties can carry a travel premium because the visit consumes more of the engineer's day.
3. Urgency. A check booked weeks ahead slots into an engineer's existing route. A certificate needed "by Friday" because a tenancy starts on Saturday is a disruption, and priced like one. The renewal window rules mean you can book up to two months early without losing any cover — use them.
4. One-off or relationship. Many engineers quote lower for repeat annual work, portfolios of several properties, or a landlord who also uses them for servicing and repairs. A one-off price-shopped visit gets a one-off price.

Note what is not on the list: the certificate itself. The paperwork is the same whoever issues it, and a £120 CP12 is not "more valid" than a £50 one.

Booking through a letting agent: watch the markup

If an agent fully manages your property, they will usually arrange the gas safety check with their own contractor and pass the cost through on your statement. That is convenient, but it is worth reading the line item. Some agents pass the engineer's invoice through at cost; others add an administration fee or use a contractor whose rates include a referral margin. A £130 charge for a one-boiler flat in a region where checks cost £60 is not unheard of.

Two questions settle it: what does the engineer invoice, and what do you add? If the answer is uncomfortable, most management agreements let you nominate your own Gas Safe engineer, or you can arrange the check yourself and simply send the agent the certificate — the legal duty is yours either way, so the paperwork must end up in your records regardless of who booked the visit.

What to ask when you book

Quotes become comparable when you pin down the same four things with every engineer:

• What is included — how many appliances the price covers, and what each extra one costs
• Whether a re-check after remedial work is included in the price or charged separately
• When you get the certificate — same-day digital delivery should be the norm in 2026, not a week of chasing
• What combining a boiler service adds — and that you will receive both documents

Five minutes of asking usually separates the engineer who quoted low and invoices high from the one whose price simply is the price.

The combined visit: CP12 plus boiler service

The single most effective way to spend less overall is to combine the gas safety check with the annual boiler service in one visit. The engineer is already at the property with tools out, so the combined price — typically £100–£160 — is usually £20–£40 less than booking the two jobs separately.

Two cautions. First, be clear about what you have booked: a CP12 does not include a service, and a service does not produce a CP12. Confirm the visit covers both and that you will receive the safety record and a service record. Second, if the boiler is under a manufacturer's warranty, an annual service by a Gas Safe engineer is usually a warranty condition — so for newer boilers the combined visit is not really optional spending, it is protecting the warranty anyway.

Failed appliances and other costs to budget for

The check fee assumes checking, not fixing. If the engineer finds a fault, they will classify it — Immediately Dangerous, At Risk, or Not to Current Standards — and where the appliance is dangerous, issue a warning notice and ask permission to disconnect it. The remedial work is then quoted separately, like any repair.

Budget-wise, the sensible planning assumptions are:

• Minor defects — a ventilation obstruction, a deteriorated seal — often cost £50–£150 to put right.
• Significant faults on older boilers can run to several hundred pounds, at which point the repair-or-replace question appears.
• Re-checks after remedial work may be included or charged; ask when you book.

One thing a landlord should never budget for is skipping the check to save the fee. The check costs less than a week's rent for most properties; prosecution under the gas safety regulations carries unlimited fines. The penalties section of our CP12 guide covers what non-compliance actually exposes you to.

Is a CP12 tax deductible?

Yes, in the normal case. The annual gas safety check is a routine cost of letting the property, so it is generally an allowable expense against rental income — the same category as insurance, agent fees, and repairs. The same goes for a boiler service and for remedial repairs that restore an appliance to working order.

Keep the invoice with the certificate. If your affairs are more complicated — the property is owned through a company, or you are unsure whether work counts as a repair or an improvement — confirm the treatment with your accountant.

How to pay less without cutting corners

Everything above points to the same short list:

• Book early, inside the renewal window. Two months of flexibility means no urgency premium and no lapsed certificate if the tenant cancels an appointment.
• Combine the CP12 with the boiler service in one visit, and with any other annual checks the property needs.
• Use the same engineer year after year. Repeat work is priced better than one-off work, the engineer already knows the appliances, and renewal reminders tend to actually arrive.
• Portfolio landlords: consolidate. Several properties with one engineer, ideally with clustered renewal dates, is cheaper per property than five engineers found five ways.
• Verify registration, then judge on reliability. Among registered engineers, the meaningful differences are turning up when agreed, issuing the certificate the same day, and reminding you next year — not £10 on the quote.

The cheapest certificate is the one you never have to think about: booked automatically inside the window, done in one combined visit, delivered digitally the same day, and stored where you and your tenants can always find it.

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