Clean Heat Market Mechanism: verifying annual fossil fuel boiler sales reports

This is guidance for verifiers on how to carry out independent assurance of annual fossil fuel boiler sales data, as required under the Clean Heat Market Mechanism (CHMM) Regulations 2025 No.81.

You should read this guidance with the CHMM Regulations. It is not intended to provide details of all the possible activities you may need to complete as a verifier as part of your assurance activities.

This guidance may also be useful to Scheme Participants who are preparing for their independent third-party verification. They need to follow the guidance on:

• who the scheme applies to and annual tasks
• how fossil fuel boiler sales, targets and credits work
• how to report online and get credits