MCS certification explained

MCS stands for the Microgeneration Certification Scheme. It is a UK quality-assurance scheme for small-scale renewable technology, including home solar. It is not a government department, but it is backed by government and industry and is written into the rules for export payments and grants.

It works on two strands. It certifies installers, checking that a company designs and fits systems to the scheme standards, and it certifies products, listing specific makes and models that have been tested. An install only counts as MCS-certified when both the installer and the key products qualify, so a certified firm fitting non-certified panels can lose that status.

There are thousands of certified installer companies across the UK, and the number offering solar runs into several thousand, so being certified is a baseline to expect rather than a rarity worth paying a premium for.

The two strands cover different things, and you want both. Installer certification means the company is approved to design and install solar to the MCS standard for the technology. That covers the design of the system, the quality of the work, commissioning it properly, the handover paperwork and after-sales support. It is the company that is certified, not an individual fitter.

Product certification means a specific make and model of panel or inverter has been tested against the MCS product standards and listed in the MCS Product Directory. The point of this strand is that the hardware itself meets a known quality bar, not just the workmanship.

Both have to line up. A certified installer that fits a panel or inverter which is not on the product list cannot register that job as MCS-certified, and without that registration you do not get the certificate. So when you check a quote, the question is not only whether the firm is certified but whether the actual kit it is proposing is listed too.

MCS is the eligibility gate for the things that make solar pay back. To claim the Smart Export Guarantee, the scheme that pays you for electricity you export, you need an MCS-certified install or one under an equivalent recognised scheme. Suppliers can ask for the certificate as proof, and some only contract with certified installs at all.

It is the same story for grants. ECO4 and the Warm Homes schemes require MCS-certified installers and products for the measures they fund. Home Energy Scotland and other devolved schemes specify MCS too. So a non-certified install can leave you unable to claim export income or any grant you might otherwise qualify for, even if the panels generate fine.

This is the practical risk worth understanding. A cheaper non-certified job can cost you more over time, because it can shut the door on years of export payments and on grant funding you were entitled to. The certificate is what unlocks the income side of solar, not just a quality badge.

You do not have to take a firm word for it. The official MCS register lets you search for certified installers by technology and postcode, so you can confirm a company is genuinely certified for solar before you sign anything. It takes a couple of minutes.

First, open the MCS Find an Installer search and look up the firm by name or by your postcode. Second, check the company name on the register matches the exact legal name on your quote, not just a similar trading name. Third, confirm it is listed for solar PV specifically, since a firm can be certified for one technology, such as heat pumps, but not another. Fourth, check the products on your quote, the panels and inverter, appear in the MCS Product Directory. Fifth, confirm the firm is also listed on its consumer code, RECC or HIES, which is covered below.

If a company cannot be found on the register, or the name does not match, treat that as a reason to pause and ask questions before going further.

MCS installers serving homeowners must also belong to an approved consumer code, either RECC, the Renewable Energy Consumer Code, or HIES, the Home Insulation and Energy Systems scheme. The codes exist to protect the buyer, and membership is a condition of staying MCS-certified, so the two go together.

The codes set rules on how a firm sells, what the contract must contain, how deposits are handled, and what warranties you get. In practice that means a couple of concrete safeguards. There are minimum warranties, including a workmanship warranty on the installation itself, and deposit or advance-payment protection through insurance-backed schemes, so money you pay up front is not simply lost if the firm fails before finishing. The exact lengths and terms are set by the code and can change, so the written contract is what to read.

If there is a problem with the work, the order to follow is clear. Raise it with the installer first and give them the chance to put it right, in writing where you can. Most issues are resolved at this stage.

If that does not work, escalate to the firm consumer code, RECC or HIES, which offers a complaints and dispute-resolution process, including arbitration, and can hold the firm to the code standards. Separately, MCS runs a technical-quality process of its own, which can audit a certified install and require defects to be put right. Underneath all of this you keep your normal consumer-law rights. The reason to check the firm is on both the MCS register and its consumer code before you commit is simply that these routes only exist if the firm was genuinely a member when you signed.