Buyer's checklist
Accreditations to check before you appoint a commercial solar installer
MCS, NICEIC or NAPIT, RECC, TrustMark, IWA, ISO 9001/14001, CHAS and Cyber Essentials Plus — what each one means for you as the buyer, and how to verify that the installer quoting you actually holds it. We publish this site; we are not an installer and hold none of these ourselves.
MCS
Required for SEG up to 50 kW
NICEIC / NAPIT
Electrical sign-off
IWA
Insurance-backed warranty
ISO / CHAS
Larger and public-sector tenders
UK commercial solar is one of the most regulated areas of the construction industry. A credible installer will hold a stack of trade-body, electrical, quality and health-and-safety accreditations — and every one of them can be checked against a public register in minutes. This page tells you what each scheme means and where to look. It is a checklist for judging installers, not a list of anything this site holds.
MCS — Microgeneration Certification Scheme
What it is: The UK industry standard for renewable technology installation. For systems up to 50 kW, MCS (or equivalent) certification is required to access Smart Export Guarantee (SEG) export tariffs; from 50 kW to 5 MW each supplier sets the evidence it accepts. The certificate evidences design and installation compliance with MCS 005 (PV) and MIS 3002 (installation method).
How to check: Search the installer at mcscertified.com. Ask for the MCS certificate number and confirm the company name on the register matches the one on your contract — not a parent or sister company. Open the register.
NICEIC or NAPIT — electrical contracting
What it is: The two main UK electrical competent-person schemes. Registered contractors are independently audited for compliance with BS 7671 (Wiring Regulations) and BS EN 62446 (Solar PV) across the DC and AC sides — grid connection, isolation, earthing and surge protection.
How to check: Verify at electricalcompetentperson.co.uk, which covers NICEIC, NAPIT, ELECSA and STROMA in one search. A firm claiming one scheme while registered with another is a sign the claim was copied, not checked. Open the register.
RECC — Renewable Energy Consumer Code
What it is: The consumer-protection code for renewable energy installations: transparent pricing, written quotations, deposit protection and independent dispute resolution. It applies to consumer contracts, so it does not automatically bind a commercial job.
How to check: Search the member list at recc.org.uk and ask the installer to confirm in writing which RECC terms it will apply to your contract. Open the register.
TrustMark
What it is: The UK government-endorsed quality scheme for trade contractors, covering customer service, technical competence and trading standards.
How to check: Search the licence at trustmark.org.uk. TrustMark is required for some domestic grant routes; for commercial work treat it as a general trading-standards signal. Open the register.
IWA — insurance-backed workmanship warranty
What it is: An insurance policy that covers installation defects even if the installer ceases trading. It is what makes a 10-year workmanship warranty worth anything.
How to check: Ask for the policy wording and the insurer's name, not just the word 'insurance-backed' on the quote. Check the policy names your site and the installed system. Open the register.
ISO 9001 and ISO 14001
What it is: International standards for quality management (9001) and environmental management (14001). Certification requires documented processes, internal audits and annual external audit. Larger corporate and public-sector buyers often specify them.
How to check: Ask for the certificate and check the certification body is UKAS-accredited. A certificate with no accreditation mark is worth less than it looks. Open the register.
CHAS, CHAS Elite and SafeContractor
What it is: Health-and-safety pre-qualification schemes used widely in commercial procurement. CHAS verifies pre-qualification under PAS 91; CHAS Elite adds enhanced criteria; SafeContractor is a comparable scheme accepted by many buyer organisations.
How to check: Ask which scheme and tier the installer holds and request the current certificate — these renew annually and lapse quietly. Open the register.
Cyber Essentials Plus
What it is: The UK government cyber-security standard, with the Plus tier independently verified. Relevant where an installer will hold your half-hourly meter data, drawings and commercial information, and required for many public-sector contracts.
How to check: Check the certificate on the IASME register. Open the register.
What this means in practice
Before you sign, confirm for the company on your contract that:
- it appears on the MCS register — SEG suppliers require MCS (or equivalent) certification for systems up to 50 kW;
- its electrical work is signed off under NICEIC or NAPIT and BS 7671;
- the workmanship warranty is insurance-backed, with the policy wording in your hands;
- any ISO, CHAS, SafeContractor or Cyber Essentials certificate is current and from an accredited body;
- the accreditation names on the proposal match the registers — a mismatch is the most common sign of a copied claim.
Three quotes from three MCS-registered installers, each checked the same way, is the cheapest due diligence you will do on the whole project.
Frequently asked questions
Why does MCS certification matter for commercial solar?
For systems up to 50 kW, Smart Export Guarantee suppliers require an MCS (or equivalent) certified installation and installer before they pay for exported electricity; from 50 kW to 5 MW each supplier decides what certification evidence it accepts, so ask your chosen supplier before you sign. Check the company at mcscertified.com and ask for the certificate number in the tender.
Is RECC relevant to commercial buyers?
RECC is a consumer code, so it does not bind an installer's commercial contracts. Its disciplines — transparent pricing, written quotations, deposit protection and independent dispute resolution — are still a useful signal of how an installer operates. Ask whether they will apply the same terms to your contract.
What is the difference between CHAS and CHAS Elite?
Standard CHAS verifies health-and-safety pre-qualification under PAS 91. CHAS Elite adds enhanced criteria around training, accident records, supply-chain management and audit frequency. Public-sector and large corporate procurement often specifies one of them.
Does this site hold any of these accreditations?
No. This site is published by SEO Dons Ltd, which does not design, supply or install solar systems. Every accreditation on this page belongs to installers — the point of the page is to help you check that the one quoting you actually holds them.
Which accreditations should I specify in a procurement?
MCS as the baseline (SEG suppliers require it, or an equivalent, on systems up to 50 kW; above that, check what your supplier accepts). NICEIC or NAPIT for the electrical work. An insurance-backed workmanship warranty (IWA or equivalent). For larger or public-sector projects, add ISO 9001, ISO 14001, CHAS or SafeContractor, and Cyber Essentials Plus if the installer will handle your building or meter data.
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