The Boiler Upgrade Scheme for installers

The Boiler Upgrade Scheme is administered by the installer, never the homeowner. Someone has to apply for the voucher, deduct the grant from the quote before a spanner is lifted, and carry that money until Ofgem pays it back after commissioning. That last part is the bit most guides skip, and it is the bit that decides whether grant-backed work helps a heating business's cashflow or strains it.

You do not need your own MCS certification to fit BUS-eligible heat pumps and get paid on the grant. Most heating engineers taking on this work for the first time do it under an experienced partner's MCS certification and administration, and that is the route this guide leads with. Holding your own MCS certification is the other way in, and it is worth reading alongside how to become MCS certified if that is the path you are weighing.

Here is the current picture, verified against Ofgem's Installer Guidance V5.1 and correct for applications properly made on or after 21 July 2026.

The short answer

Every Boiler Upgrade Scheme claim needs an installer of record: a business that holds MCS certification for the technology, an approved consumer code position, and a verified BUS installer account with Ofgem. That can be you, or it can be a partner such as Ample, administering the job while you do the work. Either way, the applicant quotes with the grant already deducted, applies for a voucher on the property owner's behalf, and Ofgem emails the homeowner to confirm consent. Once the voucher is issued there are three months to commission an air-to-water heat pump, or six for a ground source system. After commissioning and MCS certification the voucher is redeemed, and Ofgem aims to pay on the next weekly payment day. Grants run from £2,500 to £9,000 depending on technology and property.

Two routes to being the installer of record

Whoever holds MCS certification for the job is the installer of record on the voucher, whether or not they are the person on site fitting the kit. There are two ways to get there.

The route most heating engineers take when they first move into grant-backed heat pump work is to operate under an experienced partner's MCS certification and administration, such as Ample's. The partner is the installer of record on Ofgem's system: it holds the certification, runs the BUS application and redemption, and carries the grant until Ofgem pays it back. The heating engineer does the install. This route removes the account-holding, the paperwork and the cashflow exposure in one move, which is why it is the more common starting point.

The other route is to hold MCS certification directly and administer every voucher under your own account. It is the right choice for a business that wants to run BUS applications itself, and it takes longer to get there. If that is the direction you are weighing, read how to become MCS certified alongside this piece: it sets out what MCS:2025 certification actually involves and how long it takes. Ample's platform also gives certified and certifying installers access to a network of third-party training providers, though Ample itself does not train, accredit or certify anyone on either route.

Why experience matters, especially in complex cases

Ofgem's rules are precise, and getting a claim through cleanly has less to do with knowing the grant values than with how the paperwork is put together. An application only counts as "properly made" once Ofgem holds everything it needs: the eligibility evidence, the owner's consent, and any further information Ofgem has asked for. Get any of that wrong or incomplete and the clock keeps running. Ofgem gives 14 days to answer a request for further information, and late evidence may not be considered at all.

This is where an organisation processing BUS claims every week has a real advantage over one doing its first grant job. It has seen the evidence Ofgem accepts and the evidence it queries, so the paperwork tends to go in clean the first time, which is what keeps a claim on schedule and off Ofgem's desk for clarification.

That advantage is sharper on the more complicated cases. Qualifying self-builds are eligible for the scheme, but they also tend to raise more ownership and evidence questions than a straightforward like-for-like replacement, which is exactly where a claim is more likely to need extra information from Ofgem if the paperwork is not right first time. The same is true of properties without a valid EPC, where the alternative-evidence route (a recent utility bill or fuel receipt, photographs of the existing system, and an expired EPC number if there is one) has to be assembled and presented in the form Ofgem expects, not just supplied.

None of this changes what the customer pays or when the work happens. It changes whether the voucher clears in one pass or turns into a clarification request that costs time on both sides.

What the grant is worth from 21 July 2026

The grant value depends on the technology and whether the property is off the gas grid. Current values, set in the BUS regulations:

• Air-to-water heat pump: £7,500, voucher valid three months

• Air-to-water heat pump in an eligible off-gas-grid property replacing oil or LPG: £9,000, voucher valid three months

• Ground source heat pump: £7,500, voucher valid six months

• Ground source heat pump in an eligible off-gas-grid property replacing oil or LPG: £9,000, voucher valid six months

• Air-to-air heat pump, residential only: £2,500, voucher valid three months. Not claimable yet, see below

• Biomass boiler, limited circumstances: £5,000, voucher valid three months

The £9,000 uplift runs from 21 July 2026 until 31 March 2027 and applies only to air-to-water and ground source systems. To count as off-gas-grid the property must not be fuelled by mains gas, must have no record of an existing gas meter point, must not be attached to a heat network and must not be a new build. A capped or clamped gas supply still counts as being on mains gas. The system coming out has to be oil or LPG.

Grant value is fixed by the date the application is properly made, not the date of the quote. That distinction matters around any value change.

What the installer of record needs before applying

Four things, and all four are gates rather than nice-to-haves.

MCS certification for the technology being applied for, held by the installer of record. Ofgem checks this and rejects applications from businesses that are not certified for the relevant technology. Temporary MCS certification numbers cannot be used to create an account or apply for a voucher.

An approved consumer code position. Installers who have moved to the MCS Redeveloped Installer Scheme no longer need separate consumer code membership, because MCS:2025 is itself an approved consumer code for the scheme. Installers still operating under the previous MCS scheme must hold membership with HIES or RECC. Working under a partner's umbrella carries this automatically.

A verified BUS installer account. One person with legal authority acts as the authorised representative, and Ofgem verifies their identity. The account holder sends a completed account creation form with photo ID, proof of home address and a business bank statement from the last three months. Once the account exists, other users can be added to apply for and redeem vouchers. Under a partner's account, this step belongs to the partner, not to you.

An eligible property and system. England and Wales only. Social housing and new builds are out, apart from qualifying self-builds. The heat pump must replace a fossil-fuel or electric system, be sized to meet the property's full space heating demand, sit on the BUS Product Eligibility List, stay within 45kWth (or 70kWth as a cascade), and hit a minimum SCOP of 2.8. Hybrids that pair a heat pump with fossil-fuel heating are not eligible.

The upfront discount rule: the grant is fronted, not banked

This is the most consequential rule on the scheme and it became a hard requirement on 28 April 2026. The full grant value must be passed to the property owner as an upfront discount. It has to appear on the quote before the installation and on the invoice afterwards. The installer of record must not request or accept that amount from the homeowner, and the homeowner confirms to Ofgem that they received the discount as part of the consent step.

In cash terms: on a £9,000 off-gas-grid job the installer of record deducts £9,000 from the quote, the work is completed, and the amount is recovered from Ofgem after commissioning and redemption. The grant is not a subsidy that lands alongside payment for the job. It is working capital fronted and then reclaimed, and it is exactly the exposure a partner such as Ample is set up to carry instead of you.

If an application is rejected or a voucher is revoked, the ability to recover that deducted amount is restricted, which is why Ofgem strongly recommends waiting for the voucher before commissioning. Commissioning early is permitted, but the risk sits with whoever fronted the discount.

How to apply for a Boiler Upgrade Scheme voucher, step by step

1. Confirm the property and system are eligible, and identify the grant value and voucher validity period for the technology.

2. Provide a quote with the grant deducted as an upfront discount.

3. Submit the voucher application from the installer of record's BUS installer account, with the EPC certificate number if the property has a valid EPC, or alternative evidence if it does not.

4. Ofgem emails the property owner to confirm consent, verify their identity and confirm they have received the discount.

5. Ofgem runs its eligibility checks and emails the voucher, showing the issue date, expiry date, voucher ID, technology type and the grant value payable on successful redemption.

An application is only "properly made" once Ofgem holds everything needed to assess eligibility, any further information has been supplied, and the property owner's consent is confirmed. That date drives the grant value and the clocks around it, so a half-complete application is not a submitted one.

Since 28 April 2026 a valid EPC is no longer a standing eligibility requirement. Where a property has one, the certificate number is given. Where it does not, alternative evidence is provided on the owner's behalf: a utility bill or fuel receipt dated within the last three months, photographs of the existing heating system, and the number of an expired EPC if there is one.

Redeeming the voucher and getting paid

Once the system is commissioned to MCS standards and the MCS installation certificate is generated, the installer of record submits the redemption application from their BUS installer account, inside the voucher validity period. Ofgem runs final checks, including a review of the MCS certificate.

Approved redemptions are processed for payment on the next scheduled payment day, and those payment days run weekly. Ofgem is clear that it makes every effort to hold that timeframe but that short delays happen occasionally, and installers should plan accordingly. Bank details need to stay current on the account: payments are not re-issued if they fail because details were not updated.

Audits can happen at any point after an application, including after payment, and can be desk-based or on site.

The deadlines that catch installers out

Five clocks run on every grant job, and missing one costs the grant rather than delaying it.

• 120 days: the voucher application must be properly made within 120 days of commissioning if the system is already in.

• Three months: voucher validity for air-to-water, air-to-air and biomass. Six months for ground source. Expired vouchers cannot be extended, though a fresh application can be made.

• 14 days: the window to answer an Ofgem request for further information on an application. Late evidence may not be considered.

• 31 March 2027: the last date for the £9,000 off-gas-grid uplift.

• 31 December 2029: the final date Ofgem can issue vouchers under the scheme.

One consent per property at a time, too. If a homeowner consents to another installer's application first, the later one is rejected.

What changed in 2026, and why the pipeline is worth building around

The scheme was overhauled on 28 April 2026 and again on 21 July 2026. The EPC requirement went. Air-to-air heat pumps came in at £2,500, though no air-to-air product holds MCS certification yet, so no voucher can be raised against it and certification is not expected before late 2026. The upfront discount became a formal obligation. Eligibility was restructured, supplementary non-fossil heating appliances were permitted alongside a BUS heat pump, and MCS certification is written into the regulations as the definition of an eligible installer. The scheme now runs to 2030, with a published budget through to then and £295m allocated for 2025/26.

So this is a multi-year market with a fixed rulebook, not a spike to chase. The constraint on most heating businesses taking more of it is not demand. It is the working capital tied up in every grant job and the admin around each application, and both of those are exactly what an experienced partner is built to take on.

Where the money actually sits

Run the numbers on a busy month. Four off-gas-grid jobs at £9,000 of deducted grant each is £36,000 fronted and waiting on commissioning, redemption, checks and a weekly payment run. Add the quote pack, the eligibility evidence, the consent chase, the DNO notification and the certificate, and the paperwork per job runs into most of a day.

That is the real ceiling on how much grant-backed work a small firm can hold at once, whoever is carrying the cash. It is a cashflow problem wearing a compliance costume.

How Ample fits in

Ample is the MCS entity of record for every job it takes on, whether or not you hold your own MCS certification, and takes both halves of the problem off your plate. Ample handles the BUS applications and redemptions, the DNO notifications, the design review, the Insurance-Backed Guarantees and the commissioning and handover packs, so the admin per job stops being yours.

On the cash: milestone payments land within one working day of each confirmed milestone, and our BUS Advance pays the grant value on commissioning rather than leaving you to wait for Ofgem, for a fixed £200 fee. Working capital comes back in days instead of weeks, which is what decides how many grant jobs a heating business can run at once.

There is no membership fee and no lock-in. The £210 per project is a pass-through of the third-party MCS and Insurance-Backed Guarantee costs we incur on your behalf, so you pay no more than you would doing that work yourself. Read how to become MCS certified alongside this piece if holding your own certification is the route you would rather take.

Ready to take on more heat pump work?

The rules are settled and the budget runs to 2030. What limits most heating businesses is the cash tied up in each grant job and the admin stacked around it, and both of those are fixable, whether you hold your own MCS certification or work under a partner who does.

See how Ample's MCS umbrella works, or get started, and read the installer FAQs if you want the detail first. We have got your back on every job.

Frequently asked questions

Do I need my own MCS certification to claim the Boiler Upgrade Scheme?
No. The install has to be MCS certified for the technology, and MCS certification is written into the BUS regulations as the definition of an eligible installer, but that certification does not have to be yours. Most heating engineers taking on this work do it under a partner's certification and administration, such as Ample's; holding your own MCS certification is the other route, covered in how to become MCS certified.

Who applies for the Boiler Upgrade Scheme, the installer or the homeowner?
The installer of record, whether that is you or a partner administering the job on your behalf. The application goes in on the property owner's behalf from a BUS installer account, and Ofgem contacts the owner separately to confirm consent and their eligibility details.

How long does it take to get paid for a BUS voucher?
Once the redemption application is approved, Ofgem aims to process payment on the next scheduled payment day, and those run weekly. Ofgem notes there may occasionally be short delays and asks installers to plan for that.

Do you have to take the grant off the quote?
Yes. Since 28 April 2026 the full grant value must be deducted from the quote as an upfront discount, shown on the quote and on the invoice, and the installer of record must not request or accept that amount from the property owner.

How long is a BUS voucher valid?
Three months for air-to-water heat pumps, air-to-air heat pumps and biomass boilers. Six months for ground source heat pumps. Expired vouchers cannot be extended, but a fresh application can be made.

Which properties qualify for the £9,000 grant?
Properties in England or Wales that are off the gas grid, with no record of an existing gas meter point, not attached to a heat network and not new builds, replacing an oil or LPG heating system with an air-to-water or ground source heat pump. The uplift is available for applications properly made from 21 July 2026 until 31 March 2027.

Does a property still need an EPC for the Boiler Upgrade Scheme?
No. From 28 April 2026 a valid EPC is no longer a standing eligibility requirement. Where one exists the certificate number is provided; where it does not, alternative evidence is provided, such as a recent utility bill or fuel receipt and photographs of the existing system.

Can you commission the system before the voucher is issued?
It is allowed, but at the installer of record's own risk. If eligibility is not met no voucher is issued, and the discount will already have been given. Ofgem recommends waiting for the voucher.