Choosing solar panels is the easy part. Choosing the company to fit them is where most people feel unsure, and understandably so. A solar system is a 25-year investment, and the installer you pick will shape how well it performs, how much you save and who you can call if something ever needs attention.
The good news is that you can separate the excellent installers from the rest with a handful of straight questions. This guide gives you 12 to ask before you sign anything, explains why MCS certification is non-negotiable, and flags the warning signs worth heeding. It comes from Cre8 Zero, an MCS-certified solar, battery and EV charging installer based in Brighton and serving Sussex, Kent, Surrey, Hampshire and Brighton & Hove.
Why MCS certification is the first thing to check
MCS stands for the Microgeneration Certification Scheme, the recognised quality standard for renewable installations in the UK. It is not a marketing badge. It is a genuine mark of competence, and it unlocks two things you cannot afford to lose.
- The Smart Export Guarantee. You can only claim payments for exported solar if your system was installed to the MCS standard. No certification means no export income.
- The 0% VAT relief. The current 0% VAT on home solar and battery storage, in place until 31 March 2027, relies on a compliant, certified installation.
Key takeaway: if an installer is not MCS-certified, you risk losing both your export payments and your VAT saving. This is the first box to tick, not the last.
The 12 questions to ask before you sign
Work through these with any company you are considering. A strong installer will answer every one without hesitation.
1. Are you MCS-certified?
Ask directly, and ask for the certification number so you can check it. This single question protects your export income and your VAT relief.
2. Will qualified electricians carry out the work?
Solar involves your home’s electrics, so the people on your roof and at your consumer unit should be fully qualified, registered electricians. Do not accept vague reassurances.
3. What product warranties come with the panels, inverter and battery?
Each component has its own manufacturer warranty. Panels often carry 25-year performance warranties, while inverters and batteries typically carry around 10 years. Ask for the specifics in writing.
4. Do you offer an insurance-backed workmanship warranty?
This is different from the product warranties. It covers the quality of the installation itself, and being insurance-backed means it stands even if the company were no longer trading. It is a mark of a serious installer.
5. Can I see recent local references and reviews?
Ask for genuine reviews you can read yourself, ideally on independent platforms like Trustpilot and Google, and ideally from your area. Local, recent and verifiable is what you want.
6. Is your quote fully itemised?
You should see the make and model of the panels, inverter and any battery, plus scaffolding and labour, set out clearly. A single lump sum with no detail makes it impossible to compare fairly.
7. Why have you designed the system this way?
A good installer can explain their choices: why that system size, those panels, that inverter, and that placement on your roof. If they cannot justify the design, be cautious.
8. Who handles the paperwork?
A proper install involves notifying your network operator, issuing your MCS certificate and setting you up to claim the SEG. Ask who takes care of all of it, so nothing falls to you by surprise.
9. What aftercare and monitoring do you provide?
Ask how you will monitor performance (most modern systems offer app-based monitoring) and what happens if output drops. Aftercare is where the relationship really counts.
10. What finance options are available, and what are the terms?
If you plan to spread the cost, ask about the APR, the term, the total amount payable and early repayment. Finance is subject to status, so understand the detail before committing.
11. What is the timeline from order to switch-on?
A realistic installer gives you a clear schedule for survey, installation and connection, rather than vague promises. Ask what could cause delays.
12. Who do I call if there is a problem in five years?
This is the question that separates the local specialist from the here-today firm. You want a team that will still be reachable and willing to return long after the panels are up.
Comparing quotes and want honest answers to all twelve? Book a free energy assessment with our team and put us to the test.
Red flags to watch for
Alongside the questions, keep an eye out for these warning signs. Any one of them is a reason to slow down.
- No MCS certification. The single biggest red flag, for all the reasons above.
- Pressure selling. “Sign today for this price” tactics and rushed decisions are a classic warning sign. A fair price holds next week too.
- Vague or non-itemised quotes. If you cannot see what you are paying for, you cannot judge value.
- Unnamed components. An installer who will not tell you the make and model of your panels or inverter is hiding something.
- No workmanship warranty. Product warranties alone do not cover the quality of the fit.
- Wildly cheap prices. A quote far below the rest usually means a corner has been cut somewhere.
Key takeaway: trust your instincts. A reputable installer educates and reassures, rather than pressuring.
Why local really matters
Solar is a long relationship, not a one-off transaction. Panels last decades, and at some point you may want a service visit, a battery added, or simply a question answered.
A local, certified installer can return quickly and knows the area, from the housing stock to the local planning nuances across Sussex, Kent, Surrey, Hampshire and Brighton & Hove. A national company that installed and moved on cannot offer the same. When something matters years down the line, local is the difference between a quick visit and a long wait.
How Cre8 Zero measures up
We built this checklist because we are happy to be judged by it. Every Cre8 Zero installation is MCS-certified and carried out by fully qualified electricians. Our work is backed by an insurance-backed workmanship warranty, and our quotes are clear and itemised so you know exactly what you are paying for and why.
We handle the paperwork, set you up to claim the Smart Export Guarantee, and offer app-based monitoring so you can see your system working. Our 5-star ratings on Trustpilot and Google come from real customers across the South East, and because we are based in Brighton, we are here for the long term, not just installation day.
Frequently asked questions
Why should I choose an MCS-certified solar installer? MCS certification is the recognised UK quality standard for solar installations, and it is required to claim the Smart Export Guarantee and the 0% VAT relief. Choosing an MCS-certified installer protects both your export income and your VAT saving, and signals a competent, compliant install.
What questions should I ask a solar installer before signing? Ask whether they are MCS-certified, whether qualified electricians do the work, what product and workmanship warranties apply, for local references and reviews, for a fully itemised quote, why the system is designed as it is, who handles the paperwork, what aftercare and monitoring they provide, the finance terms, the timeline, and who to call years later.
What are the warning signs of a bad solar installer? Common red flags include no MCS certification, pressure selling or “today only” prices, vague or non-itemised quotes, refusing to name the components, no insurance-backed workmanship warranty, and prices that are far cheaper than everyone else.
What is an insurance-backed workmanship warranty? It is a guarantee covering the quality of the installation itself, separate from the manufacturers’ product warranties. Because it is insurance-backed, it remains valid even if the installer were no longer trading, giving you long-term protection.
Does it matter if my solar installer is local? Yes. Solar systems last decades, so aftercare, servicing and future upgrades matter. A local, certified installer can return quickly, knows the regional housing and planning landscape, and is far easier to reach years after installation than a national firm.
Ready to put us to the test?
The right installer will welcome every question on this list and answer each one clearly. That openness, backed by proper certification and genuine local reviews, is what separates a trustworthy solar company from the rest.
See how we measure up for yourself. Book your free energy assessment online, call us on (020) 3038 4595, or email enquiries@cre8zero.com, and get honest, straightforward answers before you commit to anything.
