MCS certificate
An MCS certificate is the document an MCS certified installer raises on the MCS Installations Database and gives to the customer within 10 working days of commissioning a small-scale renewable installation such as solar PV, a heat pump or battery storage. It is the proof energy suppliers ask for before paying Smart Export Guarantee rates.
An MCS certificate is the document an MCS certified installer issues to the customer after commissioning a small-scale renewable installation, confirming that the system was designed, installed and commissioned to MCS standards using MCS certified products. MCS is the Microgeneration Certification Scheme, and it covers technologies including solar PV, heat pumps and battery storage. The certificate is not a legal requirement for installing a system, but without it the customer cannot claim Smart Export Guarantee payments or access the Boiler Upgrade Scheme and ECO4.
Three things must all be true before a certificate can exist: the installation was commissioned by an MCS certified installer, it includes an MCS certified product, and the commissioning date is after 15 July 2009. The installer raises the certificate on the MCS Installations Database, known as the MID, which holds every MCS certified installation in the UK since 2008.
What an MCS certificate shows
Every certificate carries an MCS certificate number generated by the database when the installation is registered. Alongside it, the certificate records the type and model of the technology installed, the installing company and its certification details, and confirmation that the system complies with MCS standards. On a solar PV job that includes the array size in kWp, which is the figure a SEG licensee checks against the export meter data.
It is a short document, not a warranty and not an insurance policy. MCS states plainly that it will not be held liable for product failure or installation failure; those sit with the manufacturer's warranty and the installer's own workmanship guarantee or insurance-backed guarantee.
How to get an MCS certificate
You do not apply for an MCS certificate. The installer raises it, so getting one is a matter of choosing the right installer and checking the paperwork before the final payment leaves your account.
- Check the company currently holds MCS certification for the specific technology, using the Find an Installer tool on mcscertified.com, before you sign anything.
- Get written confirmation in the quotation that an MCS certificate will be issued and that the products quoted are MCS certified products.
- At commissioning, ask for the certificate in the handover pack, or ask for it to be sent electronically from the database.
- If nothing has arrived 10 working days after the commissioning date, chase the installer before you release the final payment.
For installers: handover, the MID and the SEG handoff
All MCS installations must be registered on the MID, and the certificate must be obtained from the database and provided to the customer within 10 working days of the commissioning date. The database enforces the window rather than merely recommending it: selecting a commissioning date more than 10 working days in the past triggers a mandatory extra step before a late certificate can be raised. Once generated, the certificate can be printed into the handover pack or emailed to the customer straight from the MID.
The 10 working day window is a standard, not a target
MCS requires the certificate to be obtained from the MCS Installations Database and provided to the customer within 10 working days of the commissioning date. Registering late is still possible, but the database adds a mandatory declaration step and the delay holds up the customer's Smart Export Guarantee application, which in turn holds up your final invoice.
The certificate is what starts the customer's export income, so the handoff is worth doing at handover rather than leaving to a follow-up email. The customer picks a SEG licensee, which does not have to be their current electricity supplier, and applies with their smart meter details and the MCS certificate. Ofgem does not set the tariff: SEG licensees set their own rate, contract length and terms, and the only rule is that the rate must be above zero. Eligibility runs up to 5MW for solar PV and wind, and 50kW for micro-CHP, with the installation in England, Scotland or Wales.
The same handover pack usually carries the DNO notification too, and the order the two are done in decides whether the job closes in a week or a month. Running a battery storage installation and running a heat pump installation from survey to certificate both set out where the certificate sits in the sequence.
Because the certificate is raised from commissioning data, whatever the engineer records on site is what the office has to work from. Capturing commissioning readings, the product serial numbers and the customer signature on a phone at handover, through digital site forms, removes the gap between finishing the job and being able to raise the certificate.
Sources
- MCS Certificate queriesPrimary sourceMicrogeneration Certification Scheme · accessed 2026-09-10
- MID Guidance for InstallersPrimary sourceMicrogeneration Certification Scheme · accessed 2026-09-10
- Smart Export Guarantee (SEG)Primary sourceOfgem · accessed 2026-09-10