Landlord gas safety certificates explained: who needs one, what it costs, what gets checked

If you let out a property in England, the law requires you to have a Gas Safety Record, usually called a CP12, renewed every 12 months. Here’s the practical version, written by working Gas Safe engineers in Oldham.

Who needs a CP12?

Anyone who lets a residential property with any gas appliance: a boiler, a gas hob, a gas fire, a gas oven, even an old gas water heater. That includes:

• Buy-to-let landlords (single property or large portfolio)
• Accidental landlords (e.g. inherited or moving abroad)
• Holiday lets and short-term lets
• HMOs and student lets
• Letting agents acting on the landlord’s behalf

If your tenants own and brought in their own gas appliance (e.g. their own gas cooker), you are not responsible for that appliance. You are still responsible for the gas pipework and any fixed appliances.

What the engineer actually checks

A CP12 inspection is a visual and operational check. For each gas appliance the engineer will:

• Test the appliance is working safely
• Check combustion (a flue gas analyser is used on the boiler)
• Check the flue and ventilation
• Check the pipework feeding the appliance for tightness
• Look for visible signs of corrosion or damage

The engineer will also test the gas tightness of the system from the meter, and confirm the presence and function of any required carbon monoxide alarms.

What it costs in Oldham (2026)

A typical single-property CP12 with one boiler and one cooker is £75 to £95. Multi-appliance properties or HMOs are quoted on request. Portfolio landlords usually get a discount when bundling several properties on the same day.

How long is it valid?

Twelve months from the date of inspection. You can have the new check up to two months early without losing the existing renewal date, which is useful if you are juggling several properties. We send reminders 30 days before yours expires.

What if something fails?

The engineer will tell you immediately and either:

• Issue a warning notice. You must fix the fault before the property is re-let.
• Disconnect the appliance. Required for immediately dangerous faults.

Repairs can usually be quoted on the spot, and many minor faults are fixed during the same visit if parts are stock items.

Penalties for not having one

Letting a property without a valid CP12 can result in fines, prosecution, and (most importantly) invalidates much of your landlord insurance. In a worst-case carbon-monoxide incident the consequences are far more serious.

How to book

We turn around most CP12s within 48 hours across Oldham, Rochdale, Ashton-under-Lyne and Middleton. Tell us the property address, the number of gas appliances, and the tenant’s contact details. We handle access ourselves.

See our landlord gas safety certificate service →

FAQ

Can the tenant refuse access? Tenants are required to allow reasonable access for safety checks. Document your attempts in writing if they refuse. Most resistance disappears once a written reminder lands.

Can I do a CP12 myself if I’m a Gas Safe engineer? Yes, but most landlords prefer an independent engineer for liability reasons.

Do I need a separate Electrical Installation Condition Report (EICR)? Yes. That’s a different certificate (required every 5 years) and is not part of the CP12. Some firms (not us) bundle them; we focus on gas only.