Read end-to-end by a FundingAtlas editor against the official source.
Quick answer
A government voucher in England and Wales paying a fixed contribution toward replacing a fossil-fuel heating system with a heat pump or biomass boiler. The scheme pays the installer, not the building owner, and is structured around MCS-certified installer applications — so the practical entry point is choosing an accredited installer, not filling in a portal. Best for owners of small non-domestic buildings (and homes) below the EPC and heat-loss size thresholds where electrification stacks up technically.
Funding amount
Varies
Region
Wales, England
Stage
Any stage
Provider
Ofgem (on behalf of UK Government)
Advisor view
**How the scheme actually works** The voucher is applied for by the MCS-certified installer, not the building owner — the installer takes the grant value off the quoted price. The owner's job is to choose an installer carefully, get a heat-loss calculation, and check the EPC. The grant value is fixed per technology and capped per system, not per project, so it works for typical small-building heat-pump installs and falls short on large or complex sites. **What goes wrong** Most rejected or delayed claims come down to (a) outstanding EPC recommendations for basic insulation that the owner has not addressed, (b) installer mistakes in the MCS submission, (c) trying to use the grant for a building type that does not qualify (new-build, district heat, very large commercial), or (d) misunderstanding that the grant is per-system not per-property. **Demand and pricing** Grant value is fixed nationally but contractor pricing varies widely. The grant has on occasion been increased to lift demand, and budgets are reviewed periodically. Get two or three MCS-certified quotes — the spread is often larger than the grant value.
Frequently asked questions
- Who is Boiler Upgrade Scheme really for?
- It works best for organisations that already meet the eligibility test on paper and have the operational maturity to deliver — not for businesses hoping the application will force them to formalise.
- What are the most common reasons applications are rejected?
- Weak evidence, eligibility misses, and applications that read as business as usual rather than the specific intent of the scheme. Most rejections are avoidable with earlier preparation.
- Can early-stage startups apply?
- Sometimes — but the strongest applicants usually have at least minimum trading history, a defined plan and the team to deliver. If you are pre-revenue with no plan, expect to be too early.
- How competitive is it?
- Demand routinely outstrips supply for the high-profile UK programmes. Treat any competitive call as a serious bid that needs four to six weeks of preparation, not a weekend.
- What should I prepare before I apply?
- A short written summary of what you are doing and why it qualifies, your latest accounts or forecasts, and any partner or evidence the scheme expects. Get adviser sign-off before submission.
- What happens after a successful application?
- Expect monitoring, reporting and milestone evidence. Plan the reporting cadence and internal owner before the funding lands, not afterwards.
Who it's for
Owners of small commercial premises, mixed-use buildings, and homes in England and Wales whose property is suitable for a heat pump (or biomass in eligible rural settings), with a valid EPC, no outstanding EPC recommendations for loft or cavity wall insulation, and an MCS-certified installer engaged to scope and apply on their behalf. Particularly useful for small businesses replacing end-of-life gas, oil, or LPG systems.
Probably not for you if…
Buildings outside England or Wales (Scotland and NI have separate schemes), new-build properties (excluded by design), buildings with outstanding EPC recommendations for loft or cavity wall insulation that the owner has not addressed, large commercial buildings or district-heat installations (the scheme is capped per system), social housing (separate routes exist), and projects priced around grant capture rather than genuine heating need.
Usually too early when
Advisor signal
You do not yet have a valid EPC, the EPC carries outstanding loft or cavity wall recommendations, you have not had a heat-loss calculation done, you have not engaged an MCS-certified installer, your property is a new-build, your system size or complexity sits outside the per-system cap, or your premises is in Scotland or Northern Ireland (different scheme).
Eligibility
Property owners in England and Wales meeting BUS criteria. Installations via MCS-certified installers.
Evidence you'll need
Property and installer details, EPC where required.
Application timeline
Owner obtains valid EPC and addresses outstanding insulation recommendations → engages MCS-certified installer → installer performs heat-loss calculation and produces quote → installer submits voucher application → voucher issued (typically days to weeks) → installation completed inside voucher validity → installer claims redemption from Ofgem. Most projects complete within 3–6 months of engaging an installer.
Common reasons applications fail
Outstanding loft or cavity wall recommendations on the EPC, which are a hard stop until addressed. Choosing a non-MCS installer in error. Trying to apply the voucher to a new-build, social-housing, or oversized system that does not qualify. Discovering after install that the building's heat-loss profile means the heat pump cannot meet demand efficiently — usually a sign the fabric upgrade was skipped. Quotes inflated to absorb the grant, defeating the financial case.
What improves your odds
A clean, current EPC with no outstanding insulation recommendations. A property that is genuinely suited to electrification — well-insulated fabric, sensible heat-loss numbers. An MCS-certified installer with prior experience claiming the grant. Two or three competitive quotes so the grant subsidy is not absorbed by inflated pricing. A clear plan for the disruption of installation, especially in occupied commercial premises.
Typical successful applicant
A small commercial property owner or homeowner in England or Wales replacing an end-of-life gas, oil, or LPG boiler in a reasonably-insulated building with an air-source heat pump installed by an MCS-certified contractor, using the voucher to close the gap between heat-pump and like-for-like fossil-fuel system pricing.
Common misconceptions
The grant is not paid to the building owner — it is paid to the installer who deducts it from the price. It is not available for new-builds. It is not unlimited per property — it is capped per system. It is not a Scottish or Northern Irish scheme — different programmes apply. And it does not pay for the insulation upgrades that may be required before the heat pump is viable; those have to be done first, often at the owner's expense.
What happens next
On a successful claim, Ofgem pays the installer, the owner pays the net (post-voucher) price, and the system enters its operational life. Owners often follow up with smart-control integration, on-site solar PV to offset running costs, or further fabric upgrades to improve heat-pump efficiency. For commercial buildings, the install commonly becomes part of a wider net-zero narrative for tenants, lenders, or planning.
What comes next
Owners who use BUS typically progress to broader building decarbonisation: solar PV, battery storage, EV charging, and deeper fabric upgrades. Commercial buildings that have completed BUS-funded heat replacement become natural candidates for the Public Sector Decarbonisation Scheme (if public-sector occupied) or industrial decarbonisation programmes for adjacent process-heat loads.
Funding context
BUS is the headline subsidy in England and Wales for one-for-one fossil-to-low-carbon heat replacement. It sits alongside ECO4 (low-income energy efficiency), the Public Sector Decarbonisation Scheme (large public estates), Home Upgrade Grant (off-gas low-income homes), and devolved equivalents in Scotland (Home Energy Scotland) and Northern Ireland. For small businesses, the natural stack is BUS for the heat-pump plus VAT-zeroing on qualifying energy-saving materials, sometimes alongside local growth-hub or sector decarbonisation grants for the wider building.
Related routes
Industries
Objectives