You have a rental property with a gas boiler and a gas hob, and you know there is a yearly gas check to arrange. The questions that actually cause trouble are the timing ones: when is it due, can you do it early without losing time, and by when do you have to hand a copy to the tenant. Here is how the annual CP12 works in practice.
What a CP12 actually is
"CP12" is the old CORGI form number (CORGI Proforma 12) that stuck. The correct name today is the Landlord Gas Safety Record, though almost everyone still calls it the gas safety certificate or CP12. It is the document a Gas Safe registered engineer gives you after checking the gas appliances and flues in your rental property.
The legal duty behind it sits in the Gas Safety (Installation and Use) Regulations 1998, regulation 36. It applies to landlords letting residential property in England, Wales and Scotland, and it is enforced by the Health and Safety Executive (HSE).
What the check covers
The engineer inspects every gas appliance and flue that you, as landlord, own and provide for the tenant's use. That typically means the boiler, a gas hob or cooker, a gas fire, and a gas water heater, plus the flues or chimneys serving them.
For each one the engineer checks that:
- the appliance burns gas correctly and is at the right operating pressure
- there is enough ventilation for it to work safely
- the flue or chimney is clearing combustion products properly
- safety devices function as they should
- there are no gas leaks on the installation pipework
An appliance the tenant brought and owns is their responsibility, not yours, but the installation pipework and any flue serving it can still fall to you. If in doubt, ask the engineer to note on the record what was and was not tested.
How often: the 12-month rule
The check must be carried out every 12 months, by a Gas Safe registered engineer (the register replaced CORGI in 2009). There is nothing to arrange in between beyond ongoing maintenance and dealing promptly with any fault a tenant reports.
The early renewal window most landlords get wrong
Before 6 April 2018, having the check done early reset the clock, so a cautious landlord who renewed two months ahead slowly lost days off every future deadline. An amendment to the regulations that took effect on 6 April 2018 fixed this. You can now have the check done up to two months before the deadline and keep the original deadline date (source: HSE, Gas Safety (Installation and Use) Regulations 1998 as amended, hse.gov.uk/gas/landlords).
Worked example, keeping your anniversary date:
- Last check completed: 12 September 2025.
- Legal deadline for the next check: 12 September 2026.
- Under the 2018 rules you can have the next check done any time from 12 July 2026 (two months early) up to 12 September 2026, and your deadline stays 12 September. The following year's deadline is still 12 September 2027.
- Renew earlier than that window, say in May 2026, and the clock resets: your new 12-month deadline runs from the May date, and you give away part of the year you already paid for.
The practical takeaway is to book roughly four to eight weeks before the anniversary. You get a comfortable buffer for access problems without shortening your cycle.
The 28-day deadline to give tenants a copy
Passing the check is only half the duty. You also have to put the record in the tenant's hands.
| Who or what | When it must happen |
|---|---|
| New tenant moving in | Before they occupy the property |
| Existing tenants | Within 28 days of the check being completed |
| Your retained copy | Kept for at least 2 years |
A short worked timeline: if the engineer completes the check on 12 September, an existing tenant must have their copy no later than 10 October, which is 28 days on. A new tenant starting on 1 October must receive it before they pick up the keys, not within 28 days afterwards.
Email is fine as long as the tenant has agreed to receive documents that way. Keeping proof that you sent it is worth the few seconds it takes.
What happens if you miss it
Failing to arrange the annual check, or to give the tenant their copy, is a criminal offence under the 1998 Regulations. The HSE can prosecute, with unlimited fines and, in the most serious cases involving danger to life, imprisonment. Beyond the law, an out-of-date or missing gas record is exactly the kind of thing that surfaces at the worst moment, such as a deposit dispute or an insurance claim after an incident.
There is a changing eviction angle worth noting. Under the rules in force before 1 May 2026, not giving a tenant their gas safety record could block a valid Section 21 notice. The Renters' Rights Act 2025 (Royal Assent 27 October 2025) abolishes Section 21 for new and existing tenancies from 1 May 2026, so that specific consequence falls away, but the gas safety duty itself is completely unchanged. Check the current position at legislation.gov.uk and gov.uk, because commencement details can move.
A simple routine that keeps you compliant
- Record the anniversary date (the deadline, not the date you booked) for every property.
- Book the check four to eight weeks ahead so access problems do not push you over.
- Use only a Gas Safe registered engineer, and check their ID card and the appliances it covers.
- Give existing tenants their copy within 28 days, and new tenants theirs before move-in.
- Store every record for at least two years, with proof you sent it.
Get those five things onto a calendar and the annual CP12 stops being a source of anxiety and becomes a five-minute admin task once a year. If you track your portfolio in a tool that flags renewal dates, set the alert to the deadline minus six weeks so you are always inside the early-renewal window.
This is general information, not tax or financial advice. Gas safety rules and commencement dates can change, so confirm the current position with the HSE (hse.gov.uk) and legislation.gov.uk before you act.
