MCS vs RECC for commercial solar — which accreditation actually protects you

Two acronyms come up on every solar installer's website: MCS and RECC. They're presented as a matched pair of quality badges, and most buyers nod along without examining what each actually does. For a commercial buyer, that's a mistake — because one of them is essential to you, the other was built to protect domestic homeowners and may not cover your business at all, and above a certain system size the first one may not even be available.

Here's what each one really is, and what it means when you're buying as a company.

At a glance

MCS — the technical standard (this one matters to you)

The Microgeneration Certification Scheme (MCS) is a technical certification. It covers two things: the products (panels, inverters, batteries) and the installation process. An MCS-certified installer has demonstrated they install to a recognised technical standard, and an MCS certificate is issued for each compliant installation.

For a commercial buyer, MCS matters for one concrete, financial reason beyond quality assurance: it's the gateway to the Smart Export Guarantee. To be paid for the electricity you export to the grid, your installation needs MCS certification — or a recognised equivalent, which is where system size starts to matter. Given export income is typically 20–30% of a commercial system's financial benefit, this is not a detail to leave to the installer.

The 50 kW threshold most commercial buyers fall foul of

Here's the part that catches out businesses specifically, because it sits exactly where commercial systems live.

MCS certification covers installations up to 50 kW. Below that, the path is simple: your installer is MCS-registered, your install gets an MCS certificate, you present it to a SEG supplier, you get paid for exports.

Above 50 kW, MCS is no longer the route. Solar PV remains SEG-eligible all the way up to 5 MW, but eligibility above 50 kW has to be evidenced through an equivalent certification scheme rather than MCS — Flexi-Orb is the alternative most commonly named — and individual SEG suppliers set their own expectations about what evidence they'll accept.

Read that against the sizes SMEs actually build. A commercial array is commonly 30 to 250 kWp. A 40 kWp system on a small industrial unit is squarely inside MCS. A 150 kWp array on a distribution warehouse is well outside it. The same phrase — "we're MCS certified" — means something quite different for those two projects, and an installer who deals mostly in domestic work may not volunteer the distinction.

What to do about it:

• Establish which side of 50 kW your system falls on before you discuss export income at all.
• If you're under 50 kW: insist on MCS, and confirm the certificate will be issued for your installation, not merely that the company holds registration.
• If you're over 50 kW: ask the installer to name the equivalent scheme they'll certify under, and — the step people skip — confirm with your intended SEG supplier that they accept it, in writing, before you sign. Suppliers differ.
• If you're near the line (say 45–55 kWp), know that the certification route is a real input into the sizing decision, not an afterthought. It's occasionally worth designing to stay under 50 kW purely to keep the simpler route, though rarely worth sacrificing much capacity for.

Getting this wrong doesn't stop your system generating. It stops you being paid for what you export — which quietly removes a fifth to a third of the return your payback model assumed. See commercial solar payback for how much of the case rests on export income, and grants and funding for current SEG rates.

RECC — the consumer code (this one probably doesn't cover your business)

The Renewable Energy Consumer Code (RECC) is a different animal entirely. It's not about technical quality — it's about behaviour. RECC members sign up to a code governing how they treat customers: advertising and sales conduct, quotations, contracts, deposit protection, cancellation rights, complaints handling, and aftercare. It's backed by the Chartered Trading Standards Institute.

That all sounds excellent, and for a homeowner it is. But read the name again: Renewable Energy Consumer Code. Consumer codes exist to protect consumers — individuals buying for purposes outside their trade or business. When you buy solar as a limited company, a partnership, or a sole trader acting in your business, you are generally not a "consumer" in the legal sense, and the consumer protections RECC provides largely don't apply to you.

This is the bit installers don't spell out. An installer's RECC membership is a genuine signal that they run a tidy, consumer-facing operation — but it does not extend the code's deposit protection, cancellation rights, or dispute resolution to your business the way it would to a homeowner. (The same logic applies to HIES, another consumer code you may see.)

The practical consequences are worth stating plainly. As a business buyer you have no statutory cooling-off period on the contract, no code body to escalate a dispute to, and no automatic deposit protection. Every one of those things a homeowner gets for free, you have to negotiate.

So what protects a business buyer?

Your contract. Not a code — the actual written agreement between your company and the installer. Because you can't lean on consumer protections, you need to get the protections you want into the commercial contract explicitly:

• Deposit protection — staged payments tied to milestones (deposit, delivery, commissioning), not a large upfront sum with nothing securing it. A common structure is 25% on order, 50% on delivery to site, 25% on commissioning and handover of documentation.
• Performance guarantee — a commitment to a minimum annual generation figure, with a defined remedy if it underperforms. Ask what happens in year three if output is 15% below model.
• Workmanship warranty — distinct from the product warranties, covering the installation itself for a defined period. Panel and inverter warranties come from manufacturers; the quality of the fixing, flashing and cabling is the installer's.
• Retention — holding back a percentage for a defined defects period after commissioning is standard in construction and entirely reasonable here.
• Clear timelines — with consequences for slippage, particularly where a DNO connection or roof access window is involved.
• Certification deliverables — name the certificate you're expecting (MCS or the equivalent scheme) as a contractual deliverable, not an assumption.
• What happens on insolvency — what protects your deposit and your warranties if the installer goes under before or after commissioning. Ask whether product warranties are registered directly with manufacturers in your name, because installer-held warranties are worth little once the installer is gone.

We go through these in detail in our guide to reading a commercial solar quote.

The other marks you'll see

• NICEIC / NAPIT — electrical competence schemes. The electrical work should be signed off by a registered electrician. Relevant and worth confirming.
• TrustMark — a government-endorsed quality mark, again consumer-facing but a reasonable signal.
• HIES — another consumer code, same domestic-consumer caveat as RECC.
• Flexi-Orb — the certification route that becomes relevant above 50 kW, as above.

None of these replace a solid commercial contract for a business buyer. They're signals, not guarantees of your protection.

How to sanity-check an installer's accreditations

1. Establish your system size relative to the 50 kW MCS ceiling — this determines the whole certification conversation.
2. MCS (under 50 kW) — get the registration number, verify it on the MCS register, and confirm your specific install will be certified and the certificate issued to you.
3. Equivalent scheme (over 50 kW) — get the scheme named, and confirm in writing that your intended SEG supplier accepts it.
4. Electrical — confirm NICEIC or NAPIT registration for the electrical work.
5. RECC/HIES — note it as a positive signal of a well-run business, but don't assume it protects your company. It's built for homeowners.
6. Your contract — this is where your actual protection lives. Deposit staging, performance guarantee, workmanship warranty, retention, certification deliverables and insolvency provisions, all written down.

The bottom line

For a commercial buyer: MCS is the technical standard that unlocks export income, but only up to 50 kW — above that you need a named equivalent your SEG supplier will actually accept, and that's a question to settle before signing rather than after commissioning. The consumer codes are reassuring signals but largely don't extend their protections to your business, so the cooling-off period, deposit protection and dispute route a homeowner takes for granted simply aren't there for you. Your real safety net is a well-drafted contract. Treat an installer who understands that distinction — and offers business-appropriate contractual terms — as a better bet than one who simply points at a row of logos.

The domestic-versus-commercial gap runs deeper than which code covers you — commercial vs domestic solar sets out where the two markets genuinely differ, from consumer protection to tax treatment. And for vetting the installer themselves rather than their badges, see how to choose a commercial solar installer.

To see the savings case your accredited installer should be able to stand behind, run the calculator. For the contract-level checks, read reading a commercial solar quote. And for a monthly read on standards and the wider market, subscribe to the Brief.

General information, not legal advice. Certification requirements and supplier acceptance criteria change — confirm your SEG route with your chosen supplier, and contractual and consumer-law positions with your solicitor.