How to choose an MCS installer: the checks to make and the red flags

The short answer

MCS is the certification scheme for home renewable installers, covering solar panels, batteries and heat pumps. Before you sign, look the installer up on the free MCS Find an Installer search, check they are certified for the exact technology you want, and check again before work starts. Then judge the quote and the salesperson, not just the logo.

This guide shows you how to do each check, and the warning signs that mean you should walk away.

Why MCS matters

MCS certification is not just a badge. Citizens Advice says you must use an MCS installer if you want to be paid for spare electricity through the Smart Export Guarantee, or get a heat pump grant through the Boiler Upgrade Scheme.

MCS says certified installers should design and fit your system to MCS standards, using MCS certified products. When the job is done, you should get an MCS certificate within 10 working days, plus a handover pack with product details and the workmanship warranty. Some grants and incentives need that certificate, so keep it safe.

How to check an installer on the MCS website

The MCS Find an Installer search is free. There are two ways to use it:

1. Search by name or certification number. Use the Quick Search box. This is the fastest way to check a company that has already contacted you or sent a quote.
2. Search by technology and area. Pick the technology you want (you can pick more than one), then search near your address or by region. You get a list and a map.

Each installer's entry shows their certification number, address, phone number, the regions they cover, whether they are registered for the Boiler Upgrade Scheme, which certification body checks them, and the technologies they are certified for.

When you look someone up, check three things:

• The name matches. The company on your quote should be the company on the MCS listing.
• The technology matches. Being certified for solar panels does not mean an installer is certified for batteries or heat pumps. Check each one you are buying.
• They cover your area. The listing shows the regions each installer works in.

If you can't search online, you can call the MCS helpdesk on 0333 103 8130.

When to check: three times, not once

Certification can lapse. MCS advises checking an installer when you get the quote, again before you sign, and again before the installation starts. It takes a minute each time, and it protects your export payments and any grant.

This table brings together advice from MCS and Citizens Advice. MCS also says your installer should tell you about any subcontractors, so you know who will be at your home and when.

What has changed at MCS in 2026

MCS has launched a redeveloped scheme, and certification bodies are moving installers onto it in phases, with most moving over during 2026. Two changes matter to you:

• Consumer codes are no longer compulsory. Installers used to have to join a consumer code such as RECC. Under the new scheme that is no longer required. Instead, the MCS Customer Commitment sets out installers’ responsibility to protect customers and treat them fairly. Some installers may still belong to a consumer code, so ask which protections apply to yours.
• Financial protection is compulsory. MCS says approved financial protection products are mandatory for installations for consumers under the new scheme. These include insurance-backed workmanship guarantees, and at least one also protects your deposit. Ask the installer which product they use and what it covers.

Red flags to walk away from

Which? says the company should not pressure you to buy that day, or offer large time-limited discounts. Citizens Advice suggests finding an installer yourself rather than using a cold caller. Be wary of any installer who:

• offers a big discount only if you sign today
• gives a price over the phone before anyone has visited
• gives an unusually cheap quote, or says they can finish very quickly
• promises savings that sound too good to be true
• bases the quote on averages rather than your roof and your energy use
• asks for more than 25% of the price up front (Citizens Advice says not to agree to more than that)
• can't be found on the MCS search under the name on the quote

Our 12-point checklist for comparing solar quotes covers what each quote should include once you have a shortlist.

Your rights if you change your mind or something goes wrong

If you agree the work at home, by phone or online, Citizens Advice says you have at least 14 days to cancel, starting the day after you give the go-ahead. If you ask the installer to start within those 14 days and then cancel, you may have to pay for part of the work.

If something goes wrong after the installation, MCS sets out three steps:

1. Complain to the installer. MCS says 14 days is a reasonable maximum time to expect a response.
2. Complain to MCS. MCS will acknowledge your complaint within 5 working days and update you at least every 10 working days. It says most complaints should be resolved within 8 weeks.
3. Go to the ombudsman. If you are still unhappy, or MCS hasn't resolved it within 12 weeks, eligible disputes can go to the Furniture & Home Improvement Ombudsman, free of charge. You have 12 months from the end of the MCS process to do this.

A worked example: say your inverter stops working and the installer ignores you. Allow 14 days for their reply, then up to 12 weeks with MCS before you can go to the ombudsman on time grounds alone. That is about 14 weeks in the worst case before an independent ombudsman can look at it (we added the 2 weeks MCS suggests for the installer to the 12 weeks in MCS's rules). Most complaints should be quicker: MCS aims to resolve them within 8 weeks. Keep every email and photo from day one.

Not every contract can use the ombudsman. MCS says contracts under the new scheme are eligible, but some older contracts depend on the installer's consumer code or written agreement.

What to do next

1. Decide what you want: panels only, or solar panels with a battery. Our solar savings calculator gives you a rough idea of size and savings first.
2. Get at least three quotes. Citizens Advice recommends three to compare costs. You can compare solar panel quotes through Quotes Buddy, then run each installer through the MCS search yourself.
3. Read our step-by-step guide to the installation process so you know what should happen and when.

Quotes Buddy matches you with installers. We don't install anything ourselves, so always do these checks before you sign.