MCS certificates for solar panels

What the certificate proves

An MCS certificate is a record that a renewable installation has been installed by an MCS certified contractor using approved products and processes. For a homeowner, the practical value is paperwork. It helps show that the system was installed to a recognised standard.

When people talk about solar export tariffs, this matters because Ofgem's SEG guidance says applicants for PV installations up to 50kW will be asked to demonstrate that the installation and installer are suitably certified.

Is MCS legally required?

MCS isn't the same thing as planning permission, building control or DNO connection approval. Those are separate questions. You may hear people say a non-MCS system can be legal. That can be true, but legal installation and easy SEG access aren't the same thing.

Ofgem's guidance says an MCS certificate may be used, and equivalent certification may also be recognised. The catch is practical: your chosen SEG supplier decides what evidence it needs. If you want export payments, check before you buy.

Questions to ask an installer

A good installer won't be vague about certificates. Ask whether the company is MCS certified for solar PV, whether the products are eligible, and when you'll get the certificate after commissioning.

Also ask for the handover pack. You want the MCS certificate, electrical certificates, DNO evidence, warranties, datasheets, inverter login details and a clear system diagram. Those documents can matter when you switch export supplier or sell the house.

• Who is the MCS certified contractor on the job?
• Will the certificate cover the full solar PV installation?
• What battery paperwork is provided separately?
• What happens if the installer stops trading before paperwork is complete?