MCS certification is not optional — it’s the gateway to SEG payments, manufacturer warranties, and legal consumer protections. This guide explains what MCS means, why it matters, and exactly how to find and vet a certified installer near you.
Finding an MCS certified solar installer is the single most important decision you’ll make when going solar. MCS — the Microgeneration Certification Scheme — is the UK’s quality standard for small-scale renewable energy installations. Without it, you cannot claim Smart Export Guarantee payments, your installation may not qualify for manufacturer warranties, and you lose access to important consumer protections if something goes wrong. This guide explains what MCS certification means, how to search for certified installers, what to ask, and what should be in your contract before you sign.
There are over 4,000 MCS-certified solar installation companies in the UK. Getting three quotes from certified installers takes an afternoon and can save you hundreds — or catch a problem before it becomes a costly one.
What Is MCS Certification and Why Does It Matter?
MCS (the Microgeneration Certification Scheme) is an independent quality assurance framework for renewable energy installations, including solar panels, heat pumps, and battery storage. It is operated by MCS Certified, a not-for-profit organisation, and is recognised by the UK government.
To become MCS-certified, an installer must:
- Demonstrate technical competence and relevant qualifications (typically City & Guilds or equivalent)
- Hold public liability and professional indemnity insurance
- Follow the MCS Installation Standards (MCS 001 for solar PV)
- Submit to audits of their installations — both planned and unannounced
- Register every installation on the MCS database within 10 days of completion
Critically, MCS certification is tied to a complaints and mediation process. If an MCS-certified installer does poor work and refuses to put it right, you can raise a formal complaint through the MCS Consumer Code, which can compel resolution or provide escalation to independent arbitration.
Why MCS Certification Is Non-Negotiable
There are three hard reasons why you should only use an MCS-certified installer:
1. Smart Export Guarantee Eligibility
You cannot register for the Smart Export Guarantee without an MCS Installation Certificate. No certificate, no payments — ever. Since the SEG is worth hundreds of pounds per year over the life of your system, this alone is sufficient reason to insist on MCS certification. Read more about how SEG payments work in our Smart Export Guarantee guide.
2. Manufacturer Warranties
Most tier-1 solar panel manufacturers require MCS-certified installation as a condition of their 25-year performance warranty. If your panels are installed by a non-certified company, the manufacturer can — and likely will — void the warranty. Given that panels are expected to degrade over 25+ years, a valid manufacturer warranty is a meaningful financial asset. The same applies to inverter warranties.
3. Consumer Protection
The MCS Consumer Code requires certified installers to provide clear written contracts, accurate energy generation estimates, proper commissioning documentation, and a complaints process. Without MCS, your protections are limited to general consumer law — harder to enforce and less specific about what the installer owed you.
How to Search the MCS Database
Finding certified installers near you takes about two minutes using the MCS Find an Installer tool. Enter your postcode and select “Solar PV” as the technology. The results show every certified company in your area, their certification number, and contact details.
A few things to check in the results:
- Certification status: Confirm it shows as “current” — not expired or suspended. Any installer claiming MCS status should be verifiable in real-time on the MCS website. If they’re not listed, walk away.
- Which technologies they’re certified for: An installer certified for solar PV only is not automatically certified to install battery storage. If you want panels and a battery, confirm both are covered.
- How many installations they’ve registered: The MCS database doesn’t show this directly, but asking the installer for their approximate annual volume is a reasonable indicator of experience.
Getting Multiple Quotes: What Good Practice Looks Like
The Energy Saving Trust recommends getting at least three quotes before committing to a solar installation. This is genuinely good advice. Prices for the same system size can vary by 20–30% between installers — not always because of quality differences, but often because of overhead costs, sales commission structures, or simple regional variation.
When approaching installers for quotes, do the following:
- Give every installer the same brief (system size target, roof details, whether you want a battery)
- Ask for itemised quotes, not a single headline figure
- Confirm the panel brand and model, inverter brand and model, and warranty periods
- Ask whether scaffolding, DNO notification, and commissioning are included
- Check whether the MCS installation certificate is included in the price (it must be for MCS-certified work)
Price is not the only factor. A quote 15% lower than the others should prompt you to understand why — it may reflect cheaper panels or excluded items rather than genuine efficiency.
Questions to Ask Your Installer Before Signing
| Question | What a Good Answer Looks Like |
|---|---|
| Are you MCS-certified for solar PV? | Yes, and they can provide their MCS number for you to verify on mcscertified.com |
| Who exactly will be doing the installation? | Their own employed engineers, or named subcontractors who are also MCS-certified |
| What panels are you proposing and why? | A specific brand and model (e.g. LONGi Hi-MO 6), with performance data sheet available |
| What is the inverter brand and warranty? | A named brand (e.g. SolarEdge, SMA, Sungrow) with stated warranty length |
| Is scaffolding included? | Yes — in writing |
| Will you handle the DNO notification or application? | Yes, with clarity on whether it’s G98 or G99 and who pays any fee |
| What generation estimate are you basing this on? | A specific kWh/year figure based on your postcode, roof pitch, and orientation |
| What happens if something goes wrong after installation? | Clear explanation of the warranty (installer workmanship vs panel performance vs inverter) |
| Are you a member of a consumer code? | MCS Consumer Code membership, and details of the escalation process |
What Should Be in a Good Installation Contract?
The MCS Consumer Code requires MCS-certified installers to provide a written contract before installation begins. A legitimate, well-structured contract will include:
- Full description of the equipment being installed (brand, model, quantity, rated capacity)
- Total price including VAT (which should be 0% for residential solar)
- Payment schedule (deposit amount, balance due date — typically on or after completion)
- Estimated annual generation in kWh, with the assumptions used
- Installation timeline — start date and expected completion
- Details of what happens if the installation is delayed or the equipment becomes unavailable
- Warranty coverage: workmanship (typically 2–5 years), panels (25-year performance), inverter (5–12 years)
- Commitment to register the installation on the MCS database and provide the MCS certificate
- Complaints procedure and reference to the MCS Consumer Code
Any contract that omits payment terms, doesn’t specify the exact equipment, or lacks a complaints process should be questioned. A reputable installer will expect these questions and be happy to address them.
Planning Permission: What MCS Installers Should Know
In England and Wales, most domestic solar installations are permitted development — no planning application required. However, there are exceptions:
- Listed buildings: Listed building consent is required before installing solar on a listed property, regardless of location.
- Conservation areas: Permitted development rights apply on conservation area properties but with additional conditions (panels must not be visible from a highway facing elevation in some cases). Confirm with your local planning authority.
- Flat roofs in plain view: Panels on a flat roof that project more than 1 metre above the roof surface may require planning permission.
Your installer should confirm the planning position for your specific property before work begins, and should never proceed if there’s doubt without getting it resolved. A good MCS installer knows the government’s permitted development rules for solar panels and will advise you correctly.
Red Flags: Signs of a Problematic Installer
- Cannot or will not provide their MCS number for verification
- High-pressure sales with same-day pricing or urgency tactics
- Unwilling to provide an itemised written quote
- Vague about which panels or inverter will be installed
- Requesting more than 25% deposit before installation starts
- Claiming you can get a government grant that doesn’t exist for your situation
- Unwilling to give you a 14-day cooling-off period (required by law for contracts agreed away from business premises)
- No fixed business address or landline — only a mobile number
Summary: Choosing an MCS Certified Installer
MCS certification is the baseline — not a mark of excellence, but a necessary minimum. Once you’ve confirmed certification, the differentiators are: quality of equipment specified, clarity and completeness of the contract, transparent pricing, and a track record you can verify through reviews and references. The Solar Trade Association’s installer finder can supplement the MCS database and often lists companies with strong industry standing.
Take your time, get three quotes, ask the questions above, and don’t sign anything you’re not fully comfortable with. Once you have a trusted installer lined up, our solar panel costs guide will help you assess whether the quote is fair. And when installation is complete, don’t forget to register for the Smart Export Guarantee to start earning on your surplus electricity. Use our solar savings calculator to estimate your full return before you commit.