The best solar installer for your home is an MCS-certified company that signs up to a consumer code (RECC or HIES), quotes against your real electricity use rather than a best case, and does not lean on you to sign today. Everything else, panel brand, finance offer, a shiny showroom, matters less than those four things. Skip the MCS certificate and you will struggle to get paid for the power you export, so it is the first filter, not the last.
How to choose a solar installer in the UK: the short version
Use this checklist, in this order, and most bad installers fall out at the first line.
- MCS-certified. Non-negotiable. Check the installer on the MCS Find an Installer register before anything else.
- Signed up to RECC or HIES. Both are consumer codes approved by the Chartered Trading Standards Institute, and both protect your deposit if the company folds.
- Quotes in kWp, not just pounds. A quote you cannot compare on system size is not a quote, it is a sales figure.
- States its self-consumption assumption. The savings projection should match how much you are actually home, not a household that never leaves the house.
- No pressure, no invented grant. There is no universal UK solar grant. Anyone offering you one is either mistaken or selling.
Get at least three quotes that clear all five lines, then compare them against the benchmarks in our guide to solar panel costs in the UK. The rest of this page explains why each line matters and what the good answers look like.
Why MCS certification is the one thing you cannot skip
MCS certification is not a legal licence to install solar, but it is the standard every payment scheme is built on, so in practice you should never use an installer without it. MCS stands for the Microgeneration Certification Scheme. It certifies both the installer and the products they fit to a defined standard.
The reason it matters to your wallet is the Smart Export Guarantee, the scheme that pays you for the electricity you send back to the grid. MCS lists an MCS-certified installation as an eligibility condition: "Your system was installed by an MCS certified installer using certified products. When signing up to a SEG tariff they might ask for your MCS certificate to confirm this." When you apply, the supplier's form asks for your MCS certificate alongside your smart meter data. No certificate, no straightforward route to export income. Source: MCS, Smart Export Guarantee.
It is the same story for support schemes. Where funding exists, such as the Boiler Upgrade Scheme in England and Wales or the Home Energy Scotland grant and loan, the rule is an MCS-certified installer using certified products. A company that is not on the MCS register cannot get you into any of it.
Do not take a logo on a van or a website as proof. Search the company on the MCS Find an Installer tool, and confirm they are certified for solar PV specifically, not only for another technology like heat pumps. When the job is done, your MCS certificate is registered against your property. Keep it. It is what your SEG supplier will ask for.
One thing MCS certification is not: a guarantee that the export tariff itself is generous. That is set by your electricity supplier, and the rates move constantly. We track the current numbers in our comparison of Smart Export Guarantee rates. And to be clear on the old scheme, the Feed-in Tariff closed to new applicants in 2019, so a modern install earns through SEG, not FiT.
RECC and HIES: the consumer codes that protect your money
A good solar installer belongs to a consumer code as well as being MCS-certified, and in the UK that code is almost always RECC or HIES. MCS covers the technical quality of the install. A consumer code covers the commercial side: your deposit, your contract, your warranty and what happens if the company stops trading. The two work together, and the codes are written to dovetail with the MCS installer standards.
Both are approved by the Chartered Trading Standards Institute under its Consumer Codes Approval Scheme, which is the mark to look for.
- RECC (the Renewable Energy Consumer Code). Sets consumer protection standards for businesses selling or leasing home renewable systems, covering sales conduct, contracts, deposits and dispute resolution. RECC is CTSI-approved and also a TrustMark scheme operator. Source: RECC.
- HIES (Home Insulation and Energy Systems). A CTSI-approved consumer code with specific financial protections: deposit and stage-payment protection covering up to 25% of the contract value, capped at £5,000, for 120 days from signing, plus insurance-backed guarantees running from 2 to 10 years that stand behind your workmanship warranty if the installer goes out of business. Source: HIES.
Why this matters in plain terms: solar installs usually involve paying a deposit up front to a company you met a few weeks ago. Consumer-code membership means that money is protected and there is an ombudsman or dispute-resolution route if the job goes wrong. An installer who is MCS-certified but belongs to no consumer code has covered the wiring and left your money exposed. Ask which code they are in, and check the answer on the code's own website rather than taking it on trust.
Red flags: how to spot a solar installer to avoid
The warning signs are consistent, and any one of them is reason enough to get another quote.
- "You qualify for a government solar grant." For most homeowners this is simply untrue. There is no universal UK solar grant. Support is narrow and targeted: ECO4 is linked to benefits and fuel poverty and runs to 31 December 2026, the Warm Homes Plan announced in January 2026 is still rolling out, and the Great British Insulation Scheme ended on 31 March 2026. An installer dangling a grant everyone can get is a red flag on its own.
- Today-only pricing. A discount that vanishes if you do not sign on the spot is a sales tactic, not a saving. A fair solar quote is good for weeks, because a fair installer expects you to compare it.
- No MCS certification, or a vague answer about it. If they cannot point you to their entry on the MCS register, walk away. This is the one that costs you your export payments.
- A large upfront deposit with no protection named. If they want a big deposit and cannot tell you which consumer code protects it, your money is at risk.
- Payback that sounds too good. The Energy Saving Trust models UK payback at 9 to 12 years with export payments. A pitch promising five is usually built on a self-consumption rate you will never hit. Our guide to whether solar panels are worth it shows the honest arithmetic.
- Reluctance to put the system size and component brands in writing. You cannot compare two quotes that do not both state kWp, panel model, inverter model and warranty lengths.
How to compare solar quotes fairly
Compare quotes line by line on the same terms, because a cheaper headline price often hides a smaller or lower-spec system. Line them up on these points:
| What to compare | What a good answer looks like |
|---|---|
| System size (kWp) | Stated clearly. A typical UK home system is around 4.5kWp for roughly £6,100 installed (Energy Saving Trust). Two quotes at different sizes are not like for like. |
| Panel and inverter | Named models with wattage and warranty lengths, not "premium panels". The inverter usually needs replacing around year 12, so its warranty matters. |
| MCS and consumer code | MCS-certified for solar PV, plus RECC or HIES membership. Both verifiable on the relevant register. |
| Savings assumption | The self-consumption rate is stated and matches your routine. If it assumes you are home all day and you are not, the payback shown is not yours. |
| Grid paperwork | The installer handles the DNO notification. Systems up to 3.68kW per phase are notified after connection (G98); larger ones need prior approval (G99). This should not be your job. |
| Deposit and protection | A reasonable deposit, with the consumer-code protection named. HIES, for example, protects deposits up to 25% of contract value, capped at £5,000, for 120 days. |
A note on VAT so it does not distort your comparison: solar installation is zero-rated for VAT until 31 March 2027, then it moves to the 5% reduced rate, not 20%. Every compliant installer gets the same treatment, so it should not vary between quotes. If one quote adds VAT and another does not, ask why before you read anything into the price.
Questions to ask before you sign
Five questions separate a confident installer from one hoping you will not ask.
- "What is your MCS certification number for solar PV?" A certified installer answers without hesitating and you can check it.
- "Which consumer code are you in, RECC or HIES?" The answer should be one of them, and verifiable on that code's site.
- "What self-consumption rate does your savings figure assume?" If they cannot say, the savings number is decoration.
- "Who handles the DNO notification, and is it G98 or G99?" The right answer is that they do, as part of the job.
- "Is my deposit protected, and by whom?" The protection should be named, not implied.