If you’ve started collecting solar quotes, you’ll have noticed the same four sets of initials cropping up on every website and brochure: MCS, NAPIT, RECC and HIES. They sound interchangeable. They aren’t. Each one covers a different part of the job — and one of them decides whether you can get paid for the electricity you export.
Here’s what each actually means, in plain English.
What MCS actually certifies
MCS — the Microgeneration Certification Scheme — is the UK’s recognised quality mark for small-scale renewable energy, covering technologies from solar panels and heat pumps to biomass and small wind.
It certifies two separate things:
- Products. Panels, inverters and other equipment are tested against MCS product standards covering performance, safety and factory production controls.
- Installers. Companies are assessed on training, competence and quality of workmanship, and must design and install systems to MCS installation standards — which include using MCS certified products.
That second point is worth dwelling on. MCS isn’t a course someone once attended; it’s an ongoing certification of the business, checked by an accredited certification body. When your job is commissioned, the installer registers the system on the MCS database and issues you an MCS certificate. Keep that document safe — you’re about to need it.
Why MCS is the key to SEG payments
The Smart Export Guarantee (SEG) is the Ofgem-administered scheme that requires larger licensed electricity suppliers to pay small generators — households included — for electricity exported to the grid.
To register a solar installation of up to 50kW for the SEG, Ofgem’s guidance says you must demonstrate that both the generating equipment and the installer were MCS certified (or certified under an equivalent scheme). Suppliers will ask for your MCS certificate as proof, and you’ll need a meter that can record your exports — in practice, a smart meter.
Put simply: a non-MCS installation may still generate perfectly well, but you’ll struggle to get a mainstream supplier to pay you for what it exports. A cheaper quote from an uncertified installer can end up costing you every export payment for the life of the system.
What NAPIT adds
A solar or battery installation is also an electrical installation, and that side of the job has its own rules.
NAPIT operates a Government-authorised Competent Person Scheme. Registered installers can self-certify notifiable domestic electrical work under Part P of the Building Regulations in England and Wales — meaning the work is properly notified and a Building Regulations compliance certificate is issued, without you having to arrange a separate building control inspection.
So where MCS covers the renewable system’s design and installation, NAPIT registration covers the electrical competence and the Building Regulations paperwork behind it.
What RECC covers
The Renewable Energy Consumer Code (RECC) governs how renewable energy systems are sold. It’s approved under the Chartered Trading Standards Institute’s Consumer Codes Approval Scheme and sets standards for marketing, pre-contract information, quotations, deposits, contracts, guarantees and after-sales service.
For you, the practical benefits are rules against pressure selling, protection around your deposit if the firm stops trading, and access to independent dispute resolution if something goes wrong after handover.
What the HIES consumer code covers
HIES is another CTSI-approved consumer code — it has held that status since 2015 — covering the installation of home energy products. Customers of HIES members get deposit and stage-payment protection, an insurance-backed guarantee that stands behind the installer’s written workmanship guarantee if the company ceases trading, plus free mediation and access to an ombudsman.
RECC and HIES do a similar job from slightly different angles. Both exist so the promises made at your kitchen table are backed by something stronger than goodwill.
What’s changing in 2026
The MCS installer scheme is being redeveloped. Between February 2026 and 31 March 2027, certification bodies are moving their installers across to the new scheme in phases. Under it, MCS-approved financial protection products become mandatory on consumer installations, and complaints are handled by a centralised MCS team. Consumer codes such as RECC and HIES continue alongside as an extra layer of protection installers can choose to hold — and, as RECC has reported, most of its members have chosen to stay.
Don’t take anyone’s word for it — check
Any accreditation claim should survive five minutes of checking:
- MCS — look the company up using the installer search at mcscertified.com.
- NAPIT — verify registration through NAPIT’s consumer search at napit.org.uk.
- RECC — check the members list at recc.org.uk.
- HIES — confirm membership with HIES at hiesscheme.org.uk.
We hold three of the four — MCS, NAPIT and RECC — from our base in Shepherdswell, near Dover, where we carry out solar panel installation across Kent alongside battery storage, EV chargers and air source heat pumps. That’s not badge-collecting: between them they cover every stage of your installation — the sales conversation, the electrical work, the system itself, and what happens if anything goes wrong afterwards. Whoever you choose to install your system, make sure the same boxes are ticked.
