Every UK landlord must provide a valid Gas Safety Certificate (CP12) for each rental property, renewed annually. Miss it and the penalties start at £6,000 per breach. Here is exactly what you need to do.

The legal requirement

The Gas Safety (Installation and Use) Regulations 1998 require landlords to:

  • Have every gas appliance and flue in the property inspected annually by a trusted local engineer
  • Issue a copy of the CP12 to the tenant within 28 days of the inspection
  • Provide a copy to new tenants before they move in
  • Keep the certificate on file for 2 years

What is checked

Every gas appliance

  • Boiler: combustion, flue seal, safety devices, pipework, isolation valves
  • Gas hob: burner performance, hose condition, isolation valve
  • Gas fire: flue draw, oxygen depletion device, seals
  • Any other gas appliance (space heaters, water heaters)

Gas pipework

  • Visible condition (no corrosion, no visible damage)
  • Tightness test at the meter
  • Emergency control valve labelled and accessible

Ventilation

  • Air vents unobstructed
  • Correct sizing for the appliances

What a CP12 in Leeds costs in 2026

  • 1-bed flat, 1 gas appliance: £75
  • 3-bed house, 2 gas appliances (boiler + hob): £95
  • Combined with annual boiler service: £125 (save £40 vs booking separately)
  • HMO with 3+ appliances: £150+

What happens if you fail

The engineer marks each appliance as one of three ratings:

  • At Risk (AR): Do not use until repaired. Tenant informed.
  • Immediately Dangerous (ID): Turned off on the spot. Isolated. Cannot be used.
  • Not to Current Standards (NCS): Not dangerous but does not meet current regs. Should be replaced at next opportunity.

Any AR or ID appliance means the property is not compliant. You must fix and re-test.

Penalties for non-compliance

  • £6,000 minimum per breach (unlimited maximum)
  • Prosecution possible where negligence caused harm (up to 6 months imprisonment)
  • Selective Licence in Leeds can be revoked
  • Rent Repayment Order: tenant can claim back up to 12 months rent

How CP12 fits with EICR

They are different certificates for different systems:

  • CP12 (Gas Safety Certificate): Annual, gas appliances only, by Gas Safe engineer
  • EICR (Electrical Installation Condition Report): Every 5 years, electrical installation only, by NICEIC or NAPIT electrician

Both are legally required. Both can be booked at the same visit if the engineer is dual-qualified (many are).

Best practice

  • Book CP12 in the same month each year (April is popular)
  • Book at the same time as the boiler service to save money
  • Store certificates in a shared folder accessible to your letting agent
  • Email tenant the CP12 within 28 days and get read-receipt confirmation
  • For HMOs, provide it as part of the tenant welcome pack