Choosing solar can feel technical, so here is a focused checklist of questions for solar installers to ask before signing a contract. Each question comes with the practical detail a good installer should provide, so you can compare answers and be confident in your choice, along with the documents you should expect to receive.
What exactly will you install and why?
Ask for a plain-English description of the proposed system: number and type of panels, inverter model, mounting method and any battery storage. A good installer will explain the roof area used, the expected orientation and tilt, and how those choices affect likely production. If battery storage is quoted, ask how it will connect to the PV system and whether the inverter and battery are compatible.
Can you confirm MCS certification and evidence?
Always ask whether the installer is MCS certified and to show the certificate and scope. MCS certification is the industry quality mark for small-scale renewable systems and helps ensure the system is designed and installed to recognised standards, so it's worth checking the specific MCS standard the installer follows for design and installation requirements. (mcscertified.com)
Are you covered by a consumer protection scheme?
Ask which consumer code or protection scheme covers the work and what that protection actually does for you. We operate under the HIES protection scheme and can show the membership paperwork, deposit protection and dispute resolution route we use. Membership gives you extra routes if something goes wrong, and it's worth checking on any contract you're offered. (hies.org.uk)
What guarantees and warranties come with the system?
Request a written list of manufacturer warranties for panels, inverters and batteries, plus the installer's own workmanship warranty. Manufacturer warranties and installer workmanship warranties are different things, so ask for both in writing, and expect the exact warranty documents to be passed on alongside a clear statement of workmanship cover.
How will you calculate likely savings and export payments?
Ask for a site-specific production estimate and the assumptions behind it, such as panel orientation, shading and household consumption. If you plan to export surplus energy, ask how the Smart Export Guarantee works and whether the installer will help with registration or recommending suitable SEG tariffs. The SEG allows small generators to receive payment for exported electricity, and suppliers publish their own rates and terms. (ofgem.gov.uk)
Who handles permissions, wiring and safety checks?
Ask who applies for building control or planning, if needed, who certifies the electrical work, and what testing will be carried out at handover. A copy of the electrical safety certificate and commissioning report should be provided once the system goes live.
What is the payment schedule and finance route?
Ask for the payment schedule in writing: deposit, staged payments and final payment on satisfactory commissioning. If finance interests you, ask how to apply. We offer spread-payment and 0% payment options through our flexible solar finance page, though the finance terms themselves come from our finance partner. Don't sign until you have the written schedule and finance paperwork you expect.
How long will installation and commissioning take?
Ask for a realistic timetable with key milestones: survey, ordering, installation and commissioning. A reasonable installer will explain the events that commonly shift a timeframe, such as ordering delays or planning checks, and how they'll communicate changes so you're not left waiting without updates.
What aftercare and maintenance do you provide?
Ask what routine maintenance you should expect and whether monitoring, service plans or remote diagnostics are offered. Find out how to read system performance data, what service packages are available, and what the response process looks like if a system needs an emergency visit.
Red flags to watch for
Vague answers to certification or protection questions. A genuine installer will show MCS documentation and HIES membership clearly. (mcscertified.com)
Pressure to sign immediately without written details. You should always get a full contract and time to review it.
Requests for unusually large deposits without deposit protection. Deposits and staged payments should be documented and explained clearly.
How we present our offer
As an MCS-certified, HIES-protected installer, we give a clear written proposal, an expected generation estimate, copies of MCS and HIES paperwork, full warranty details and a staged payment plan. If you'd like one of our team to walk you through a proposal in person or online, request a survey and get a free quote.
Keep this checklist with your quote and use it to confirm each item has been supplied before you sign. If you'd like help interpreting a quote you already have, our team will review it and point to any missing information.