What is a CP12?
A CP12 (Landlord Gas Safety Record) is the certificate Gas Safe registered engineers issue after inspecting gas appliances and pipework in a rented property. Landlords must arrange a gas safety check every 12 months and keep records for at least two years. The CP12 is that record. Without it, landlords cannot legally let their property.
You must issue a copy to the landlord within 28 days of the inspection. If a new tenant moves in, they must receive a copy before occupation.
What must be included — the legal requirements
The Regulations specify exactly what appears on the certificate. Missing any of these fields makes the record non-compliant:
- •Name and address of the landlord (or letting agent)
- •Address of the property inspected
- •Description and location of each appliance and flue inspected
- •Date of inspection
- •Name, company name, and Gas Safe registration number of the engineer
- •Results of all safety checks carried out
- •Any defects identified, and action taken or recommended
- •Signature of the engineer carrying out the work
Safety checks you must document
For each appliance, your CP12 must record whether you checked the following:
- •Gas tightness test on the installation
- •Burner pressure and gas rate (where test point is accessible)
- •Flue flow test and flue integrity check
- •Ventilation — adequate provision per manufacturer spec
- •Operating pressure correct per appliance data plate
- •Safety device function (flame supervision device, overheat stat, etc.)
- •Appliance status: Satisfactory, At Risk (AR), or Immediately Dangerous (ID)
Common mistakes that invalidate the record
These are the errors most likely to cause problems on inspection or investigation:
- •Omitting the Gas Safe registration number — this is the single most common error
- •Not recording flue inspection results for every appliance on site
- •Using 'N/A' for mandatory checks without a written reason
- •Failing to mark appliances as ID or AR when defects are found
- •Not issuing a copy to the tenant within 28 days of inspection
- •Recording only the appliances that were working — condemned appliances must still be listed
The legal basis: Regulation 36 of the 1998 Regulations
The CP12 is grounded in Regulation 36 of the Gas Safety (Installation and Use) Regulations 1998 (as amended). Regulation 36(3) requires every landlord to ensure an annual check is carried out on every gas appliance and flue by a Gas Safe registered engineer. Regulation 36(6) requires the landlord to retain the record for at least two years, and to provide a copy to existing tenants within 28 days and to new tenants before they move in.
Non-compliance is enforced by the Health and Safety Executive under the Health and Safety at Work etc. Act 1974. Fines are unlimited on indictment; in the Magistrates' Court, penalties commonly run to £6,000 per breach per appliance. In a fatal incident, landlords and engineers have been prosecuted for manslaughter — most recently in the 2013 Genner case and the 2019 Shepherd case. Your CP12 is the primary document an investigator will reach for.
Appliance status — Satisfactory, AR, ID
Every appliance on the certificate must be classified. The Gas Industry Unsafe Situations Procedure (GIUSP, maintained by IGEM) defines the three statuses:
- •Satisfactory — the appliance passed all safety checks and is safe to use
- •At Risk (AR) — one or more fault(s) exist that could cause danger. Requires written warning to the responsible person, who must agree what happens next
- •Immediately Dangerous (ID) — a fault that is likely to cause injury or death. You must either turn off the gas supply with permission, or (if permission is refused) issue written warning, report to the gas emergency service provider (0800 111 999) and leave a RIDDOR-reportable record
- •Not Current Edition (NCE) — appliance doesn't meet the current standard but is not unsafe. Record it, don't condemn it
The 28-day tenant notification rule
Regulation 36(6) requires landlords to give existing tenants a copy of the CP12 within 28 days of the inspection. New tenants must receive a copy before occupation. The landlord is the duty-holder here, but if you deliver via a letting agent who forgets, the landlord is still liable — and so are you if a tenant later complains the record wasn't issued.
Best practice: email a PDF copy to the landlord the same day as inspection, and keep the email as proof. HSE accepts electronic copies (per HSE circular L56 para 39). A read receipt, or a reply from the landlord, removes any doubt about delivery.
Validity, the 10-2 month window, and renewal
A CP12 is valid for 12 months from the inspection date. You can do the next inspection up to 2 months before the anniversary without shortening the validity — the new certificate simply carries the same anniversary forward. This 10-2 month rule (introduced in 2018) lets engineers book landlord checks around their own schedule without forcing customers to 'lose' a month.
Example: previous inspection 15 June 2025, valid until 14 June 2026. If you re-inspect on 10 May 2026, the new CP12 runs until 14 June 2027, not 9 May 2027. Record the original due date on the new certificate so the landlord can see the continuity.
Record retention and digital evidence
Regulation 36(6) sets a two-year minimum retention period. In practice, most engineers keep records for six years to cover the limitation period under the Limitation Act 1980 for contract claims, and twelve years if the work involved a deed.
Paper triplicates fade, get lost, or end up illegible. Digital records — signed PDFs stored with a timestamp and an email audit trail — satisfy HSE guidance and are easier to produce at inspection. Some managing agents now mandate digital records as a condition of being on their approved contractor list.
What to do if the landlord or tenant denies access
If you can't access the property, the landlord's Regulation 36 duty isn't extinguished — they must still show they took reasonable steps. Document your attempt in writing: date, time, method of contact, what you told them about the consequences. HSE guidance (L56, paragraph 159) lists acceptable steps as repeated attempts to contact the tenant, reminder letters, and (if still refused) legal action for access.
For you as the engineer, the trail you leave matters. A dated record of the attempt protects you if the landlord later pretends they couldn't get you out. TradeDoc AI lets you issue a 'no-access' record as a formal document — signed, dated, stored — so the engagement is on file if a dispute arises.
How to issue a CP12 quickly and accurately
Paper certificates and generic Word templates are slow and error-prone. You either fill them in on site (difficult when it's cold and you're on your knees), or you type them up later from your notes and risk getting details wrong.
TradeDoc AI generates a fully compliant CP12 in about two minutes. Enter the property details, appliance information, and safety check results, and it produces a professional PDF you can email directly to the landlord from your phone before you leave the job.
All required fields are built into the template so nothing gets missed. The record is stored in your document vault for easy retrieval if a landlord asks for a copy later.
