The Department for Energy Security and Net Zero (DESNZ) published responses to two consultations on 31 October 2025, confirming that it is planning to proceed with the proposal to mandate MCS as the sole certification scheme for clean heat measures1. The two consultations were Certification Requirements for Clean Heat Schemes, and Clean Heat Market Mechanism: Revisions ahead of Scheme Year 2 (2026/27)1.
The mandate would cover the Boiler Upgrade Scheme (BUS), ECO4 (the Energy Company Obligation), Warm Homes: Social Housing Fund (WH:SHF), Warm Homes: Local Grant (WH:LG), and the Clean Heat Market Mechanism (CHMM)1. MCS said the government "confirmed it is planning to proceed with the proposal to mandate MCS as the sole certification scheme for clean heat measures"1. The announcement covers England, Scotland and Wales through the UK-wide schemes named; no separate rates or nation-by-nation figures were given1.
MCS said it has been defining, maintaining and improving quality in the sector for almost two decades, and that in that time there have been more than 2.2 million MCS certified installations by close to 6,000 certified installers1. It also said its product certification scheme certifies products against MCS Standards, "ensuring installations are high-quality, efficient, and safe", including installations paid for by householders themselves and those going into new builds1.
MCS has redeveloped its installer certification scheme, which it says will focus more on how installers deliver quality to consumers, rather than administrative checks1. Installers will move over to the new scheme throughout 20261.
"As a charity-owned company, we are focused solely on improving quality and consumer protection for the greater good of the sector."
Why it matters for households
Certification sits behind whether a heat pump or other clean heat measure can be funded under a government scheme, so a single mandated scheme narrows the question of which installer requirements for grants apply. For a household, the practical effect is that grant-funded work under these five schemes would be carried out by MCS certified installers, whose work is covered by the scheme's standards and consumer protection arrangements1. MCS describes its role as giving "everyone in the UK confidence in home-grown energy"1.
The change also touches installations that are not grant-funded: MCS said its product certification covers products against MCS Standards for installations paid for by householders themselves and those going into new builds1. What the mandate means for heating appliance standards and certification more broadly has not been reported beyond the five named schemes1.
What happens next
MCS said it looks forward to supporting its installers as they move over to the new scheme throughout 20261. The consultation responses were published on 31 October 20251. No further dates for implementing the mandate have been reported1.