What Is a CP12 and Which App Actually Issues One? A UK Landlord Gas Safety Guide (2026)
CP12 is the trade name for the Landlord Gas Safety Record. Here is what UK law requires, who can legally issue one, and what to check in the software a Gas Safe engineer uses to create it.
TLDR: A CP12 is the trade name for the Landlord Gas Safety Record. Any landlord with a gas appliance must have it checked annually by a Gas Safe registered engineer, keep the record for 2 years, and give the tenant a copy.
A landlord asks for “the gas certificate.” The agent asks for “the CP12.” The engineer’s invoice calls it a “Landlord Gas Safety Record.” All three want the same piece of paper, and that gap is exactly where a renewal gets missed.
Software that actually issues one needs to do more than hold a template: it has to verify the engineer, capture the right fields, store the signed record, and track the next renewal date. The law comes first, then what to check in the app.
Updated 6 October 2026.
What is a CP12, and who has to have one?
A CP12 is the common trade name for the Landlord Gas Safety Record, the document a Gas Safe registered engineer issues after checking the gas appliances and flues in a rented property. Under the Gas Safety (Installation and Use) Regulations 1998, Regulation 36, a landlord must ensure each relevant appliance and flue is checked for safety within 12 months of being installed, and at intervals of not more than 12 months after that. The duty applies to any landlord, housing association, local authority, hotel, college, boarding school or hostel that provides a gas appliance for someone else’s use, confirmed directly on HSE’s own gas safety guidance for landlords.
The regulation covers England, Wales and Scotland. Northern Ireland runs its own separate instrument, the Gas Safety (Installation and Use) Regulations (Northern Ireland) 2004, with equivalent landlord duties under its own numbering.
Why does “CP12” cause confusion?
“CP12” is not a legal term. It comes from CORGI Proforma 12, the form once used by the Council for Registered Gas Installers, the body the Gas Safe Register replaced in 2009. The nickname outlived the body that issued it. HSE’s own guidance confirms the document “was previously referred to as a gas safety record, certificate or CP12 form” and is now formally the Landlord Gas Safety Record. A landlord, letting agent and gas engineer can use three different names for the same document without anyone being wrong.
A CP12 is also easy to confuse with paperwork that looks similar but answers a different question. A boiler service record, which a manufacturer’s warranty may require, confirms a boiler was serviced; it does not satisfy the landlord’s annual safety-check duty on its own. A one-off installation or commissioning certificate confirms a new appliance was fitted correctly; it is not a substitute for the recurring annual check once the tenancy is under way. If the paperwork on file does not list every gas appliance and flue in the property, the check date and the engineer’s Gas Safe registration number, it is not doing the job of a CP12, whatever it is labelled.
What does a CP12 legally require?
Who can carry out the check?
Only a Gas Safe registered engineer, working themselves or as an employee of a person HSE has approved for the purpose, can legally carry out the check. The regulation itself ties the duty to that approval, not to general plumbing or heating experience.
What must the record show?
The finished record must show, at minimum, a description and location of each appliance or flue checked, the check date, the property address, the landlord’s name and address, any defect found and remedial action taken, and the engineer’s name, registration number and signature, per HSE’s record-keeping guidance.
Which dates actually matter?
Three dates matter more than the paperwork’s name: the check is due at least every 12 months, the landlord must keep the record for at least 2 years from that date, and an existing tenant must get a copy within 28 days of the check (a new tenant gets the latest copy before moving in). A tenant who never receives a current copy can report the landlord directly to the HSE, per Gas Safe Register’s landlord guidance, which also confirms that from 1 October 2022 a working carbon monoxide alarm is required in every room with a fixed combustion appliance, cooking appliances excluded.
What does good CP12 software actually do?
A phone, a PDF template and a signature are not enough on their own. Software built to issue a CP12 properly needs to do four specific things:
- Verify the engineer. The record is only valid if a Gas Safe registered engineer carried out the check, so the app should tie the certificate to that engineer’s own registration number, not a free-text name field.
- Capture the required fields correctly. Every appliance and flue checked, defects found, remedial action taken, the property address and the landlord’s details need structured fields the engineer cannot skip, not a single notes box.
- Store a tamper-evident, signed record. Once signed, the stored record should not be silently editable afterwards, so it still proves what was checked and when if it is ever challenged.
- Track the renewal date and alert someone before it lapses. The 12-month clock resets the moment a check is done, so the software needs to hold that date and surface it again with enough notice to book the next visit.
A landlord-ready export matters too: a finished PDF a reader can forward or print to a new tenant, a letting agent or an HSE inspector, not a login someone else has to set up just to see one document.
Where does Checker fit into this?
Checker issues the Landlord Gas Safety Record as part of its wider certificate suite. Our Gas Reports feature keeps landlord gas safety records, commercial certificates and breakdown reports in one library tied to the job and customer, and our Annual Service Reminder tracks the renewal date and prompts the booking rather than leaving it to memory. Checker does not submit the finished record to the Gas Safe Register or any other registry; the engineer still completes and signs the check, and the landlord or tenant still gets the PDF.
Checker has three plans: LITE at £10.99 a month, PRO at £19.99 a month and PRO+ at £25.99 a month, all plus VAT, with unlimited digital records and reports on every plan. Renewal reminders, the customer database and the Xero integration, which syncs invoices and payments both ways, sit on PRO and PRO+, not LITE. PRO+ adds unlimited sub-users at £10.99 a month each, each with their own login on one shared account.
Checker is one of several apps that can issue a CP12. The table below compares it with two dedicated certificate apps on the points that matter for this job.
| App | Built for | CP12-specific capability | Renewal reminders | Price (checked 6 Oct 2026) |
|---|---|---|---|---|
| GasCert (iCertifi) | Gas, oil, heating and heat pump certificates specifically; no quoting or invoicing shown on its own pages | Covers CP1, CP12/LGSR, breakdown and gas test/purge records; enter property, landlord and appliance details once, then generate a print-quality PDF; full offline working with later sync | Configurable reminder window (14, 30, 45 or 60 days ahead) plus a one-tap reminder listing every property due for a given landlord or agent | £24.99/month or £149.00/year; VAT treatment not stated on the pricing page checked |
| Checker | Gas, electrical, oil and other trade certificates plus quoting, invoicing and job management in one app | Landlord Gas Safety Records sit in the same job record as the certificate’s invoice and the customer’s other paperwork; does not submit to the Gas Safe Register directly | Annual Service Reminder on PRO and PRO+; not included on LITE | LITE £10.99/month (certificates only, no reminders); PRO £19.99/month (adds reminders, CRM and Xero/QuickBooks/Sage sync); all plus VAT |
| Gas Certificate App | Gas certificate creation plus quoting, invoicing and job and customer records from one app | Landlord Gas Safety Record (CP12) is one of its domestic certificate options, created and sent from mobile or desktop, with an offline mode for new certificates | Service reminders the customer can accept or decline, so the engineer sees which annual jobs still need booking | £20/month plus VAT, or £216/year plus VAT (around £18/month); per user; SMS credits sold separately |
App: GasCert (iCertifi)
Built for: Gas, oil, heating and heat pump certificates specifically; no quoting or invoicing shown on its own pages.
CP12-specific capability: Covers CP1, CP12/LGSR, breakdown and gas test/purge records; enter details once, generate a print-quality PDF; full offline working with later sync.
Renewal reminders: Configurable window (14, 30, 45 or 60 days) plus a one-tap reminder listing every property due.
Price: £24.99/month or £149.00/year; VAT treatment not stated on the page checked.
App: Checker
Built for: Gas, electrical, oil and other trade certificates plus quoting, invoicing and job management in one app.
CP12-specific capability: Landlord Gas Safety Records sit in the same job record as the certificate’s invoice; does not submit to the Gas Safe Register directly.
Renewal reminders: Annual Service Reminder on PRO and PRO+; not included on LITE.
Price: LITE £10.99/month; PRO £19.99/month; all plus VAT.
App: Gas Certificate App
Built for: Gas certificate creation plus quoting, invoicing and job and customer records from one app.
CP12-specific capability: Landlord Gas Safety Record (CP12) is one of its domestic certificate options, with an offline mode for new certificates.
Renewal reminders: Service reminders the customer can accept or decline.
Price: £20/month plus VAT, or £216/year plus VAT; per user.
One independent, dated signal beyond each vendor’s own pages: on the UK App Store, GasCert shows a 5.0-star rating from 1 rating, a thin, new review base, while Gas Certificate App shows 4.2 stars from 232 ratings, a far larger one. A near-perfect score on a handful of reviews and a solid score across hundreds are different kinds of evidence.
Put a number on it for a single-user, certificates-only comparison: Checker LITE runs £109.99 a year plus VAT, £131.99 total, with unlimited certificates and reports but no reminders. Checker PRO at £199.99 a year plus VAT, £239.99 total, adds reminders, a customer database and Xero, QuickBooks and Sage sync. GasCert lists £149.00 a year, VAT treatment unstated on the page checked, so confirm that directly. Gas Certificate App lists £216 a year plus VAT, £259.20 total, per user, with SMS credits billed separately. These are the providers’ own listed annual rates for one user, checked 6 October 2026; a multi-engineer team should weigh each provider’s own per-user terms too, since those change the total.
See how a certificate, its reminder and its customer record sit against the same job before you commit to anything. Get Started Free
Further reading
These cover related ground:
- For a wider shortlist of job-management platforms that can also handle Gas Safety Records, see The Best Software for Gas Safe Records and Certificates.
- For the workflow of sending an existing record to a landlord or tenant and keeping proof it arrived, see How to Send a Gas Safety Record to a Landlord or Tenant and Keep Proof.
- For the fuller list of certificates and records a UK trade business needs to track beyond CP12, see UK Trade Certificates and Records to Track in 2026.
What should a landlord check before the next CP12?
Run through this before the next check is due:
- Confirm the last check date and work out the 12-month deadline for the next one.
- Confirm the engineer booked is Gas Safe registered, and check their registration number against the Gas Safe Register directly if unsure.
- Confirm the record on file lists every gas appliance and flue in the property, not just the boiler.
- Confirm the current tenant has a copy, given within 28 days of the check, and that a new tenant gets the latest copy before moving in.
- Confirm the record is kept somewhere it can still be produced in 2 years, not only on the engineer’s own phone.
Frequently asked questions
What does CP12 actually stand for?
CP12 comes from CORGI Proforma 12, the numbered form once used by the Council for Registered Gas Installers before the Gas Safe Register replaced it in 2009. The name stuck as trade shorthand; the document’s formal name is the Landlord Gas Safety Record.
How often does a CP12 need renewing?
At least once every 12 months, and within 12 months of an appliance’s installation if it is new. The clock resets from the date of each check, so the next one is due 12 months after that, not from any earlier date.
Who can legally issue a CP12?
Only a Gas Safe registered engineer, carrying out the work themselves or as an employee of a Gas Safe registered business. A landlord cannot carry out their own check, and an unregistered engineer cannot issue a valid one even if a registered engineer later signs off on it.
What happens if a landlord has no valid CP12?
The annual check is a legal duty the HSE enforces. A tenant who has not received a current copy can report the landlord to the HSE directly, so a lapsed CP12 is an enforcement risk, not only a paperwork gap.
Does software like Checker submit the CP12 to the Gas Safe Register for me?
No. These apps help an engineer complete, store and track the record; the engineer still carries out and signs the check, and the finished PDF goes to the landlord or tenant, not to a registry.
Authoritative sources
- Gas Safety (Installation and Use) Regulations 1998, Regulation 36
- HSE: gas safety checks, who needs them
- HSE: who can carry out a gas safety check
- HSE: gas safety check records and what to keep
- Gas Safe Register: landlord gas safety responsibilities
- Gas Safety (Installation and Use) Regulations (Northern Ireland) 2004
- Checker current pricing
- Checker feature list
- Checker Xero integration description
- GasCert (iCertifi) product page
- GasCert (iCertifi) pricing
- GasCert on the UK App Store
- Gas Certificate App
- Gas Certificate App on the UK App Store
- Best Software for Gas Safe Records and Certificates
- How to Send a Gas Safety Record to a Landlord or Tenant
- UK Trade Certificates and Records to Track in 2026