The steps, in order
- Get quotes from MCS certified installers. Each should show the grant taken off the price.
- Accept a quote. The installer applies to Ofgem on its online system, with details of you, the property and the heat pump.
- Confirm when Ofgem emails you. You have 14 days to confirm the installer is acting for you. Ofgem may also phone or visit.
- Ofgem issues a voucher in the installer's name, for the grant amount.
- The installer fits and commissions the heat pump, within 3 months of the voucher for air source and air-to-air, or 6 months for ground source.
- The installer claims the voucher. You pay the price with the grant already taken off.
Before you accept a quote
The quote is where the grant first appears, and Ofgem's guidance says it should be clear and itemised, showing the grant as a deduction. Since the rules changed in 2026, the installer must take the voucher value off the quote and may not ask you to pay that amount unless the application is refused or the voucher revoked. A quote that asks for the full price up front, with the grant to follow, is not how the scheme works. Our guide to the grant on your quote shows what to look for.
This is also the time to settle anything that could affect the application: whether a gas meter is capped, whether the property has had a heat pump grant before, and who exactly owns it. The eligibility rules set out each one.
Your confirmation: the step you control
Once the installer applies, Ofgem contacts the property owner to check that the installer is acting with their agreement. The email gives you 14 days to confirm. If you do not, the application may be rejected, and the installer would have to start again. If you are expecting the email and it has not arrived, check spam and ask the installer which email address they gave. More on what the email asks and how to answer it in the consent email guide.
The voucher and its clock
The voucher is the approved grant, issued in the installer's name. It has a deadline: 3 months from issue for air source, air-to-air and biomass, and 6 months for ground source, because of the ground works. Within that time the heat pump must be installed and commissioned, and the voucher redeemed. Ground source vouchers also cannot run past 31 March 2030, and Ofgem cannot issue any voucher after 31 December 2029.
The clock is mostly the installer's to manage, but it affects you: agree a fitting date well inside the window, and ask what happens if a delay on their side puts it at risk.
Applying after the heat pump is fitted
The scheme allows a retrospective application, made after the installation. Ofgem's guidance says it must be properly made within 120 days of commissioning, and that the owner carries more risk: if it is refused, there is no grant, and the installer can ask you for the full price. GOV.UK words the time limit differently, saying the installer must commission and install the heat pump within 120 days of applying. Either way, applying before the work is the safer route. If a decision goes against you, only the installer can ask Ofgem to review it, within 28 days: see if the grant is refused.
Who does what
| Who | Their part |
|---|---|
| Property owner | Accepts a quote; confirms the application within 14 days of Ofgem's email; answers any check from Ofgem. |
| Installer | Must be MCS certified and in a consumer code; applies; deducts the grant from the quote; fits and commissions within the voucher period; claims the voucher; can ask for a review. |
| Ofgem | Receives the application, contacts the owner, issues the voucher, pays the installer, decides any review. |
| MCS | Certifies installers; may run its own checks on installations. |
An illustrative timeline
This example uses only the scheme's own time limits; real applications vary. A homeowner accepts a quote for an air source heat pump at the start of a month, and the installer applies the same week. Ofgem's email arrives a few days later and the owner confirms the next day, well inside 14 days. Once the voucher is issued, the installer has 3 months to fit, commission and claim it, so a fitting date a few weeks later leaves a comfortable margin. The grant appears on the final invoice exactly as it did on the quote. For a ground source system, the same sequence runs with a 6-month voucher.
Common hold-ups, and how to avoid them
- Ofgem's email goes unseen. Give the installer an address you check, and look in spam when you expect it.
- The owner on the application is not the person who answers. For joint owners or a company, agree beforehand whose details go on it.
- The grant band is wrong. A home on oil with a capped gas meter applied for at £9,000 will not get it. Settle the gas question before the quote is accepted.
- The fitting slips. Agree a date well inside the voucher's 3 months (6 for ground source).
Before an installer applies, it is worth knowing that the home qualifies and which amount applies. Who qualifies and how much you get cover those questions, and the oil and LPG rate explains why the application date matters for oil and LPG homes.