MCS, grants and export
How to Choose a Solar Installer in the UK
Choosing the right solar installer is as important as choosing the right panels. This guide covers how to find, check and vet a UK solar installer: from verifying MCS registration and reading a quote properly to spotting lead-generation middlemen and knowing what the contract must say before you sign.
Useful reference. Gary Does Solar is a UK solar advice channel focused on helping homeowners make the right buying decisions without commercial bias. "Let Me Help You Choose A Solar Installer" walks through how Gary vets and recommends installers to his audience. Channel: Gary Does Solar.
MCS registration is the starting point, not the finish line
MCS certification is required for any installer doing grid-connected solar work that needs to issue an MCS certificate. But being on the register tells you the company met the standard when they were assessed. It does not tell you about customer service, subcontracting practices, or whether they will still be trading in two years to honour a workmanship warranty. Use MCS as the minimum entry requirement, then do your own checks on top.
1. Start with the MCS installer database
Go to mcscertified.com and search by postcode. The database shows which companies hold current MCS certification for solar photovoltaic installation in your area. Note the company's registered name exactly: it is not unusual for marketing brands and legal trading names to differ, and the MCS certificate must be issued in the registered name.
If a company you are considering does not appear on the database, or if their registration has lapsed, they cannot issue the certificate you need for Smart Export Guarantee registration, ECO4 funding, or the Warm Homes Local Grant. Remove them from your shortlist at this stage.
2. Get at least three written quotes
A thorough written quote names the panel manufacturer and model, the wattage and number of panels, the inverter brand and model, the estimated annual yield in kWh for your roof's orientation and shading profile, the total installed price including scaffolding and DNO notification fees, and the payment schedule. If any of these elements are missing, ask for them in writing.
Price variation between MCS-registered installers for identical specifications on the same roof is often significant. Three quotes help you establish whether you are being quoted a reasonable market rate or something at the high or low extremes. Very low quotes sometimes reflect cheaper panels, a lower-warranty inverter, or a subcontracting arrangement that adds a link in the warranty chain.
3. Read reviews on independent platforms
Check Trustpilot and Google Business for each company. Look at the volume and spread of reviews over time: a company that has been trading five years with consistent reviews is more reassuring than one with only a handful of recent entries. Read the critical reviews and note how the company responds. A firm that addresses complaints directly and resolves them is very different from one that ignores them or posts defensive replies.
Also search for the company name plus the word "complaint" or "problems" in a search engine. This surfaces issues that reviewers may not have posted on the standard platforms.
4. Ask how they handle DNO notification
Before a grid-connected solar system can be energised, your installer must submit a G98 or G99 notification to your distribution network operator (DNO). G98 applies to smaller systems (typically up to 3.68 kW inverter output per phase with no battery export); G99 applies to everything else and can take up to 45 working days to clear. Ask the installer which applies to your system, who submits it, whether it is included in the quoted price, and what the typical approval timeline has been on recent jobs.
An installer who cannot answer this question clearly, or who says you can simply energise the system without DNO notification, is not operating correctly. DNO notification is a legal requirement before energising any grid-connected generation.
5. Find out who actually does the work
Some companies in the solar market are primarily lead generators. They invest in advertising, collect your details, and pass the job to a subcontracted installation team. There is nothing inherently wrong with a reputable company that uses trusted subcontractors, but you should know the arrangement in advance and confirm who holds the MCS certification.
Ask directly: who are the people who will be on my roof? Are they your employees? If they are subcontractors, who holds the MCS certification that will appear on my certificate? The installer named on your MCS certificate bears the accountability for the quality of the work.
6. Understand the warranty and after-sales terms before signing
Panel manufacturers typically offer a 25-year performance warranty. The installer must offer a separate workmanship warranty covering the installation itself: 10 years is a reasonable minimum. Ask what happens to the workmanship warranty if the installation company ceases trading. Some installers are members of a deposit protection or guarantee scheme; ask for details in writing.
Read the contract before signing. It should state the panel and inverter models, the total price, the payment schedule, the warranty terms in full, and the cancellation rights. Under the Consumer Rights Act, you have a 14-day cooling-off period for contracts agreed at your home. Be cautious about any installer who presses you to sign on the day and waive this right.
Frequently Asked Questions
What is MCS certification and why does it matter for choosing a solar installer?
MCS (Microgeneration Certification Scheme) certification means the installer has been independently assessed against a recognised quality standard. More practically, only MCS-registered installers can issue the certificate you need to register for the Smart Export Guarantee (SEG), which pays you for surplus electricity you export to the grid. Without an MCS certificate, you cannot access SEG payments, ECO4 funding, or the Warm Homes Local Grant for solar. Check any installer's current MCS registration at mcscertified.com before inviting them to quote.
How many solar installer quotes should I get?
Get at least three written quotes from MCS-registered installers. Price variation between companies for the same roof is often substantial. Beyond price, comparing three quotes lets you spot the differences in panel quality, inverter brand, and what is and is not included in the price. A company that refuses to provide a detailed written quote is a warning sign in itself.
What are the red flags to watch for when choosing a solar installer?
The most common red flags are: no current MCS registration number they can point you to, pressure to sign on the same day the salesperson visits, a quote that gives only a total price with no itemised breakdown, vague answers about DNO notification, warranties described verbally rather than in a written contract, and large deposits demanded in cash or bank transfer before work begins. A reputable installer is happy to let you take the quote away and compare it against others.
Get a quote from our MCS-certified team See MCS installations