CP12 Gas Safety Certificate: A Practical Guide for Engineers and Landlords

"CP12" is what most people still call the Landlord Gas Safety Record. The name comes from an old CORGI form number. The form is long gone, but the legal duty behind it has not changed. This guide covers Great Britain. Northern Ireland has its own, very similar, regulations.

What the law requires

The duty comes from regulation 36 of the Gas Safety (Installation and Use) Regulations 1998. In short, a landlord must:

1. Have every gas appliance and flue they provide safety-checked at least every 12 months by a Gas Safe registered engineer, and keep pipework and fittings maintained in a safe condition.
2. Keep each record until two further safety checks have been carried out (roughly two years).
3. Give a copy to existing tenants within 28 days of the check.
4. Give a copy to new tenants before they move in. For lets of 28 days or less, you can display it prominently in the property instead.

Tenant-owned appliances, and any flue that serves only a tenant's appliance, are not covered by the landlord's duty. The landlord is still responsible for the installation pipework, and HSE recommends including all flues in the check.

The "MOT-style" renewal window

Since 2018, a landlord can have the check done up to two months before the deadline and keep the original expiry date. So if the current record runs out on 30 June, a check on 5 May still gives a new record valid to 30 June next year. A check done any earlier resets the date.

What a valid CP12 must contain

• The date of the check
• The address of the property
• The name and address of the landlord (or their agent)
• A description and location of each appliance and flue checked
• Any safety defect found and the remedial action taken
• The engineer's name, signature and Gas Safe registration number (theirs or their employer's)
• Confirmation that the check covered flue effectiveness, combustion air supply, operating pressure or heat input, and safe operation

To support that, engineers record readings and results for each appliance. That is where paper forms fall down. Handwriting gets misread, boxes get skipped and the copy the tenant receives is often hard to read.

Common CP12 mistakes

• Missing appliances. A gas fire in a back bedroom that nobody mentioned. If it is not listed, it was not checked.
• Blank defect fields. "N/A" and an empty box mean different things to an auditor.
• Wrong landlord details. Using the agent's address in the landlord field when it should be recorded as "agent for".
• Late copies. The check happened on time, but the tenant did not get a copy within 28 days.
• Lost records. A landlord who cannot produce the records for the last two checks when asked has a problem, even if every check was done.

Issuing a CP12 on site with CertBox

CertBox is built for engineers who would rather finish the paperwork before they leave the driveway:

• Fill in the record on your phone, with a row for each appliance and set fields for each check, so nothing gets skipped. Filling in and checking a certificate is free.
• Send it when you are done. Downloading, emailing, sharing or printing a certificate needs Pro, the 14-day trial, or a one-off payment for that certificate. See pricing.
• A secure link for the landlord, tenant or agent. They open it in a browser and do not need an account or pay anything.
• A QR code on every certificate, so anyone holding the PDF can check it is genuine and has not been edited.
• Renewal reminders on Pro. Your customer is reminded 60 and 30 days before the record expires, so next year's job comes back to you.

For landlords: keeping on top of renewals

If you own more than one property, the hard part is not the check. It is remembering when each one is due. In CertBox's free landlord account, you add each certificate to the property it belongs to, and its expiry is tracked from then on. You can filter by address, certificate type or expiry date, and you get a weekly email listing anything falling due in the next 60 days. Landlords never pay CertBox. See how landlord tracking works.

Frequently asked questions

Is a CP12 the same as a gas safety certificate?

Yes. "CP12", "gas safety certificate" and "landlord gas safety record" all mean the same annual record required by regulation 36.

Do I need a CP12 if the property only has a gas hob?

Yes. Any gas appliance the landlord provides, including a hob, must be safety-checked every year.

Can I email the CP12 to my tenant?

Yes, if your tenant is happy to receive it that way and can open it. You must still give a paper copy if they ask, and the record must be printable, kept secure and identify the engineer.

What happens if a landlord does not have a valid CP12?

Failing to meet gas safety duties is a criminal offence, enforced by HSE. In Wales, it also stops a landlord serving a section 173 "no-fault" notice. England's equivalent, section 21, was abolished on 1 May 2026.

Does a CP12 apply in the Republic of Ireland?

No. Ireland has its own system for gas installers. CertBox's Irish rental gas safety inspection record helps you capture the inspection, but it does not replace the document your gas installer registration body requires.

Sources

Checked against these on 2026-10-20.

• Gas Safety (Installation and Use) Regulations 1998, regulation 36
• Gas Safety (Installation and Use) (Amendment) Regulations 2018
• HSE: Gas safety record for landlords
• HSE: What landlords need to check
• HSE: Landlords FAQ
• HSE INDG285: A guide to landlords’ duties
• Renting Homes (Wales) Act 2016, Schedule 9A
• House of Commons Library: Renters’ reform in England

Corrected and updated 2026-10-20. This article is for general guidance only and does not constitute legal or professional advice. Always refer to the relevant standards and consult qualified professionals for definitive requirements.