MCS, RECC and HIES: what solar installer accreditation actually means

Solar installation sits in a part of the trades world with more overlapping accreditation schemes than most, and it's not always obvious to a homeowner which ones actually matter and why. Three names come up repeatedly: MCS, RECC and HIES. They cover different things, and understanding the difference makes it much easier to judge whether a quote from a given installer is one to trust.

MCS, the Microgeneration Certification Scheme, is the foundation most other things sit on top of. It operates at two levels: it certifies products, confirming that panels, inverters and batteries meet recognised performance and safety standards, and it certifies installers, confirming that a company has qualified staff, proper processes and a functioning quality management system. For most homeowners, the practical reasons MCS certification matters are concrete rather than abstract. Registering for the Smart Export Guarantee generally requires an MCS certificate, or an equivalent scheme certification such as Flexi-Orb, for the installation — without it, exporting surplus electricity for payment generally isn't possible regardless of how good the equipment is. Many panel and inverter manufacturers also require an MCS-certified installation to honour their product warranty, so an uncertified install can quietly void cover you're assuming you have. MCS-certified installations also carry the MCS Guarantee, a scheme-backed workmanship warranty that gives homeowners some recourse if the installer that did the work later stops trading, which is a real risk in a trade that has seen installer businesses come and go.

RECC, the Renewable Energy Consumer Code, is a different kind of protection layered on top of MCS rather than a replacement for it. Formed in 2006 and approved by the Chartered Trading Standards Institute, RECC sets standards for how renewable energy installers deal with consumers commercially — covering marketing claims, the information given before a contract is signed, deposits, contract terms, guarantees and after-sales service. It's worth knowing that the requirements around consumer-code membership for MCS-registered installers have been subject to change, with some trade commentary describing a move away from mandatory consumer-code membership for certain scheme work in 2026. Rather than assume a fixed rule either way, the safest approach is to check an installer's current status directly on mcscertified.com or recc.org.uk before treating either scheme's membership as guaranteed alongside the other.

HIES, the Home Insulation and Energy Systems Contractors Scheme, is a separate consumer-protection accreditation that also covers solar PV installers, alongside other renewable and energy-efficiency trades. Getting onto the HIES scheme involves background and credit checks on the business, supplying customer and supplier references that can be independently checked, and proof of both public liability and employers' insurance. What HIES membership adds for a homeowner is largely financial protection around the transaction itself: deposit protection, stage-payment protection, and insurance-backed guarantees that sit behind the installer's own promises, plus access to a CTSI-approved alternative dispute resolution service if something goes wrong. This matters most in the scenario every homeowner worries about but hopes never happens — the installer going out of business partway through, or shortly after, the job.

Put together, these schemes cover three different risks. MCS is mainly about the technical quality of the installation and unlocking export payments and manufacturer warranties. RECC is mainly about how the sales process and contract are conducted. HIES is mainly about financial protection if the business itself fails. A strong installer will typically hold MCS certification as standard, and it's reasonable to ask whether they also hold RECC or HIES membership, or an equivalent, as an extra layer of protection, particularly for a larger job involving a deposit paid well in advance of installation.

It's also worth checking that any certification quoted is current rather than assuming a logo on a van or an old certificate number is still valid, since scheme membership can lapse or be withdrawn. Flexi-Orb is sometimes accepted as an equivalent scheme to MCS for certain purposes, including SEG registration, so if an installer quotes Flexi-Orb rather than MCS, it's worth asking exactly what that covers rather than assuming it's identical. Regardless of which scheme or schemes an installer holds, it's also sensible to ask to see evidence of their own public liability insurance directly, since scheme membership and a company's day-to-day insurance position aren't always the same thing to check.

In practice, a short checklist covers most of what matters before signing anything: ask for the installer's MCS certificate number and check it against the MCS database rather than taking a logo on a van or website at face value, ask which consumer-protection scheme, if any, backs the contract and what that covers, and ask specifically how your deposit is protected if the company were to cease trading before the job starts. None of this guarantees a perfect installation, but it materially reduces the chance of being left without recourse if something does go wrong.

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