Boiler Upgrade Scheme Annual Report
UK – Ofgem’s annual report of Boiler Upgrade Scheme (BUS) activity reveals that over 39,000 vouchers worth more than £295.5 million were issued between 1 April 2025 and 31 March 2026.
Launched in May 2022 to support the decarbonisation of heat in buildings, the BUS provides upfront capital grants towards the cost of installing approved heat pumps and, in limited circumstances, biomass boilers in homes and small non-domestic buildings in England and Wales.
During the fourth year of the scheme Ofgem says it received 45,880 applications, an increase of 19% on applications in the previous year. After completion of pre-installation eligibility checks, 39,435 vouchers worth over £295.5 million were issued.
During Scheme Year 4, Ofgem paid grants worth £233.1 million, supporting the installation of 31,104 low-carbon heating systems. This brings the total value of grants paid since the start of the scheme to £560.3 million, supporting 80,098 low-carbon heating systems.
Since the start of the scheme, 97.6% of grants paid have been for air source heat pumps and around 76.3% were for the replacement of fossil fuelled heating systems, like gas boilers.
The report also reveals that, as of March 2026, 1,789 active installers were registered under the BUS and the top 10 installers (by application volumes) are responsible for over 36.5% of all grant applications received in Scheme Year 4.
Ofgem adds that 1,042 applications were audited in Scheme Year 4 with an initial compliance rate of 93.1%. It notes that following an audit, where possible, applicants are instructed to take corrective action. As such some of those initially assessed as being non-compliant may subsequently be brought into compliance.
Ofgem also closed 876 compliance investigations in Scheme Year 4, of which 367 (41.9%) were found to be non-compliant. Through its compliance action and other administration activities in Scheme Year 4, we prevented £3.6 million of public funds being paid incorrectly and identified a further £1.2 million for recovery.
The full report is available here.
