How to Find a Good Solar Panel Installer

A good solar panel system can last 25+ years. A poor installer can leave you with a leaking roof, a badly performing system, and no meaningful recourse. Finding the right company to do the work is arguably more important than which panels you choose.

Why MCS Certification Is Non-Negotiable

The Microgeneration Certification Scheme (MCS) is the UK's quality framework for small-scale renewable energy installations. An MCS-certified installer has been assessed against a defined standard and is subject to ongoing compliance checks.

Here's why it matters in practice:

Smart Export Guarantee (SEG): You can only register for SEG payments — money your energy supplier pays you for electricity exported to the grid — if your installation was completed by an MCS-certified installer. Without MCS, you cannot legally claim SEG. Over 25 years, this is worth thousands of pounds.

Building regulations compliance: Many MCS-certified installations qualify as permitted development and follow a self-certification route. Non-MCS installations may require separate building regulations approval.

Consumer protection: MCS-certified installers must adhere to complaint procedures and are subject to the scheme's disciplinary process. You have a formal route for redress if things go wrong.

Manufacturer warranties: Some panel and inverter manufacturers require MCS installation as a condition of their product warranty. Check before you assume.

You can verify any installer's MCS certification at mcscertified.com. Search by company name or postcode. If they're not there, they're not certified — whatever they tell you.

TrustMark Registration

TrustMark is a government-endorsed quality scheme that covers tradespeople including solar installers. TrustMark-registered businesses have undergone financial checks, skills assessments, and customer satisfaction monitoring.

For domestic installations, using a TrustMark-registered business also provides access to the government's Dispute Resolution Service — a free mediation service if things go wrong. You can check TrustMark registration at trustmark.org.uk.

Not every good installer is TrustMark-registered, but registration is a positive signal. When comparing two otherwise similar companies, prefer the registered one.

Checking Reviews Properly

Trustpilot reviews are a reasonable starting point but need interpreting carefully:

• Look at the volume of reviews, not just the score. A 4.8 rating from 12 reviews tells you less than a 4.6 rating from 400 reviews.
• Read the negative reviews and specifically the company's responses. How do they handle complaints? Are the responses defensive or genuinely constructive?
• Check when reviews were written. A flood of 5-star reviews in the past month followed by silence is sometimes a sign of solicited reviews rather than organic feedback.
• Search for the company name plus "complaints" or "problems" on Google and consumer forums like MoneySavingExpert. Systemic issues tend to surface there.

What to Check Before Signing

Adequate insurance: Your installer should have public liability insurance (minimum £2 million) and, if relevant, professional indemnity insurance. Ask to see a certificate.

Company longevity: How long have they been trading? Check Companies House for incorporation date and filed accounts. A company trading for less than two years takes on more risk.

Staff employed vs. subcontracted: Some companies sell you a system and then subcontract the actual installation to a third party you've never spoken to. Ask directly who will be physically installing your system and whether those individuals are MCS-certified.

Local presence: A local company with a physical address and genuine local reviews is generally preferable to a national aggregator that subcontracts everything. If something goes wrong, you want someone you can actually reach.

GivEnergy All-in-One 5kW Hybrid Inverter

£1,200

rated power kw

5

max pv input kw

7.5

mppt channels

2

battery voltage v

48V

View on Amazon

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Getting Multiple Quotes

Three quotes is the minimum. The spread between the cheapest and most expensive quote for the same specification can be substantial — £1,500–£2,500 is not unusual. See our separate guide on getting solar panel quotes for exactly what a good quote should contain and the questions to ask each installer.

JA Solar JAM54D41 450W N-type TOPCon

£82

watt peak

450

efficiency pct

22.8

dimensions mm

1722 x 1134 x 30

weight kg

21.5

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Affiliate link — we may earn a small commission at no extra cost to you

Red Flags to Watch For

• No physical address on the website or quote
• Pressure to sign on the day — a legitimate installer won't withdraw an offer if you want 24 hours to think
• No site survey before providing a quote — any serious quote requires at least a Google Maps/Satellite assessment, and most should involve a physical visit
• Vague specifications — your quote should name the specific panels and inverter model, not just say "high-quality panels"
• No output estimate — every quote should include a projected annual generation figure in kWh and estimated savings
• Unusual payment terms — be cautious of requests for large upfront deposits (more than 25–30%) before any work has started
• "This price is only available today" — this is a sales tactic, not a real constraint

How to Find Installers

Aside from recommendation from people you trust (always the best route), the MCS installer finder and TrustMark directories are the best starting points. Comparison services can generate multiple quotes with one submission, though be aware that these services earn a referral fee and should be used as a starting point rather than a definitive recommendation.

Once you've found two or three candidates, use our quotes guide to make sure you're comparing like for like.

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