CP12 due-date calculator
Enter the date of the last landlord gas safety check. We'll show when the next one is due and the earliest date you can do it without moving the due date.
The rules this uses
- Every 12 months. Landlords must have each appliance and flue they provide checked within 12 months of installation, then at intervals of no more than 12 months. GSIUR 1998 reg 36
- Up to 2 months early keeps the date. A check done within the 2 months ending with the deadline is treated as done on the deadline. Reg 36A, HSE FAQ
- Tenant copies. Within 28 days of the check for existing tenants. Before move-in for new tenants. HSE
- Keep the record until two further checks have been carried out (HSE's FAQ says 2 years). HSE: gas safety record
How we show dates: we show the due date as the same calendar date 12 months on (e.g. checked 15 March 2026, due by 15 March 2027). To be safe, book it before that date. Reg 36A also lets a landlord, once per appliance, do a check up to 2 months late, but only to line up the dates of appliances in the same property. This calculator doesn't cover that. This is a guide, not legal advice. Rules apply in England, Scotland and Wales. Northern Ireland has its own regulations.
How often is a landlord gas safety check (CP12) needed?
At least every 12 months. The landlord must have each gas appliance and flue they provide checked by a Gas Safe registered engineer within 12 months of installation and then at intervals of no more than 12 months (Gas Safety (Installation and Use) Regulations 1998, regulation 36).
Can the check be done early without losing the date?
Yes. Since 6 April 2018, a check done in the 2 months before the deadline is treated as if it was done on the deadline, so the next one is due 12 months after the original date (regulation 36A).
When must tenants get a copy?
Existing tenants must get a copy within 28 days of the check. New tenants must get one before they move in (HSE).
How long must the record be kept?
Until two further gas safety checks have been carried out (HSE gas safety record guidance). HSE's FAQ puts this as keeping the record for 2 years.
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