Landlords
Do I need a CP12 as a landlord in Hertfordshire or London?
3 min read · Last updated · Reviewed for accuracy before publishing
Yes. If you let a property with any gas appliance, flue or pipework, the law requires an annual Landlord Gas Safety Record — the CP12 — carried out by a Gas Safe registered engineer. You must give tenants a copy within 28 days of the check (or before they move in), and keep records for at least 2 years. Good condition is no exemption, and the HSE says breaking the regulations could mean a substantial fine and/or a custodial sentence.
What is a CP12, and what does the check cover?
A CP12 is the Landlord Gas Safety Record, the annual certificate a Gas Safe registered engineer issues after checking every gas appliance, flue and pipework you supply in a rented property. Under the regulations the engineer must examine the effectiveness of the flue, the supply of combustion air, the appliance's operating pressure or heat input, and that it operates safely.
Appliances the tenant owns aren't yours to certify, but the pipework serving them is.
The renewal window worth knowing
You can renew a CP12 up to two months before its expiry and keep the original renewal date — so there's no reason to run it to the wire. We track expiry dates across your properties and book the renewals before you'd have thought to chase them.
Portfolios
One number for every property: checks scheduled, certificates delivered digitally, reminders before each renewal, and a tidy audit trail if anyone ever asks. That's the whole point — compliance that runs itself.
“The renewal window is the most under-used rule in lettings — renew up to two months early and you keep your original date. There is never a reason to run it to the wire.”
Sources
- HSE — Gas safety: landlords and letting agents (check up to 2 months before the deadline and keep the original date; copy to tenants within 28 days; keep the record 2 years; breaches "could result in a substantial fine and/or a custodial sentence"; accessed 19 Oct 2026)
- HSE — Gas safety check records and what to keep (at least two years, or until two further checks if you use the early-check flexibility; new tenants get a copy before they move in; accessed 19 Oct 2026)
- Gas Safety (Installation and Use) Regulations 1998, regulation 36 (12-month checks; copy to existing tenants within 28 days of the check; accessed 19 Oct 2026)
- Gas Safety (Installation and Use) Regulations 1998, regulation 26(9) (after work on a gas appliance the engineer must examine the effectiveness of any flue, the supply of combustion air, its operating pressure or heat input (or combustion performance where that is not reasonably practicable) and its safe operation; accessed 19 Oct 2026)
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