What MCS certification is
MCS, the Microgeneration Certification Scheme, certifies installers of small-scale renewable technologies, including heat pumps and solar panels. A certified firm appears on the MCS register, "Find an installer", with a certification number, the technologies it is certified for, the regions it covers, whether it is registered for the Boiler Upgrade Scheme, and the certification body that certified it.
For a homeowner, certification matters in two practical ways. The grant depends on it: only MCS certified installers who belong to a consumer code can take part in the Boiler Upgrade Scheme, which is £7,500 for most homes that qualify. And a certified installer registers each completed installation, which produces the MCS certificate.
One technology at a time
Certification is given for each technology separately. That is the single most useful thing to know when checking a firm. Many installers are certified for solar panels and batteries; fewer are certified for heat pumps. A firm whose register entry lists only solar is not, by that entry, certified to fit your heat pump, however well it fits solar.
So when you look a firm up, read the technologies line first. "Air source heat pump" (or heat pumps generally) needs to be there. If it is not, ask the firm which business will actually do the work and sign it off.
The standards behind it
Certified installers work to MCS standards. Two matter most for heat pumps:
- MIS 3005-D, the heat pump design standard. MCS republished it as version 2.0 in December 2025. It is the basis of the heat-loss calculation and the sizing of the system, which is why asking for the design in writing is a fair request of any certified installer.
- MCS 020 a), the sound calculation. In England, an air source heat pump installed without a planning application must comply with it. Since 29 May 2026 it is the only sound standard that counts for that purpose.
Since 28 April 2026, MCS has also been the only certification accepted for the grant. If older material mentions other schemes for heat pump installers, it predates that change.
What MCS certification does not cover
- Your contract. Deposits, payment stages, warranties and complaints are covered by the installer's consumer code, which is a separate check.
- Building regulations sign-off. That comes through a competent person scheme or building control: see competent person schemes.
- Price and service. The register says nothing about whether a quote is fair or how a firm treats customers.
- Other trades. Electrical and plumbing work have their own registration routes.
Checking it yourself
Search the firm's name or certification number on MCS "Find an installer". Confirm heat pumps are listed, that "Registered for the Boiler Upgrade Scheme" says Yes if you want the grant, and note the certification body. Then carry on with the rest of the check sheet.
The MCS certificate at the end
When a certified installer completes a job, it registers the installation with MCS, and the MCS certificate follows. Ask when you will receive it, and keep it with your house documents. A buyer of your home, or a future engineer, may ask for it, and the grant depends on the installation being carried out by an MCS certified installer.
If a firm cannot tell you when the certificate will arrive, or says it is not needed, check its register entry again before going further.
When one firm sells and another installs
Some heat pump jobs are sold by one business and fitted by another. That is not wrong in itself, but it changes who you need to check. Ask which firm will design the system, which will fit it, and which will register the installation with MCS and apply for the grant. The firm that registers and applies is the one whose register entry matters most, and the contract should name it or explain the arrangement.