Eight questions to ask before you sign a solar quote

Most solar quotes look reasonable on the front page. The differences are in the small print — what's included, what's optional, and how the after-sales actually works. The questions below are the eight most useful to ask before you sign anything. None of them are unreasonable for an installer to answer.

1. Are you MCS certified, and what's the certificate number?

MCS (Microgeneration Certification Scheme) is the standard the UK solar industry self-regulates against. Two reasons it matters:

• SEG eligibility. Most major suppliers' export tariffs require an MCS-certified install. Without one, you can't claim the Smart Export Guarantee.
• Quality signal. MCS membership requires audits, ongoing training, and a complaints process. It's not a guarantee of perfect work, but a non-MCS installer is a real flag.

The certificate number is checkable on the MCS public register. Worth doing.

2. Are you also a member of RECC or HIES?

RECC (Renewable Energy Consumer Code) and HIES (Home Insulation & Energy Systems Contractors Scheme) are the consumer-protection codes layered on top of MCS. Either gives you:

• Limits on deposit size before installation
• A defined complaints process
• Insurance-backed warranty on the workmanship guarantee

Not legally required — but their absence means your only recourse is the small-claims court. Most reputable installers carry one.

3. What exactly is in the quoted price?

A complete quote should itemise — even briefly:

• Panels (model, brand, kWp, count)
• Inverter (model, brand, single string vs optimisers vs micro-inverters)
• Mounting and rails
• Cabling, isolators, and the generation meter
• Scaffolding and access
• DNO notification (the network operator paperwork)
• MCS certification and handover documents
• Labour
• 0% VAT applied where eligible

Things often quoted separately and easy to miss:

• Bird-proofing mesh — usually £200–£400 if needed
• Optimisers per panel (if not part of the base inverter design)
• Consumer-unit upgrade if your current one isn't solar-compatible
• Battery (if discussed separately)
• Roof repairs or new tiles if the survey finds issues

If a quote has only a single round number with no breakdown, ask for the line items.

4. What's the panel and inverter warranty — and what's the workmanship warranty?

Three different things, and they get conflated:

• Panel warranty. Typically 25 years on power output (panels still produce at least 80% of original capacity). Some Tier-1 brands extend this to 30.
• Inverter warranty. Usually 10–12 years. The inverter is the most likely component to fail in that window.
• Workmanship warranty. The installer's own guarantee on the install itself — typically 2–10 years. This is the one to read carefully. It covers leaks, loose connections, mounting issues, and bad commissioning.

If the workmanship warranty is 12 months only, that's a red flag.

5. What scaffolding do I need, and is it included?

Scaffolding is one of the bigger sources of quote-to-quote variation. A 2-storey detached with easy ladder access might need none. A 3-storey terrace with party-wall constraints might need £1,000+ of scaffolding.

Confirm:

• Whether scaffolding is included or extra
• Who arranges and pays for it
• How long it'll be up (most installs are 1–3 days)
• Any pavement licence needed if scaffolding goes onto the public footway

6. How will you handle the DNO application?

The DNO (Distribution Network Operator — the regional company that owns your local power lines) needs to know about your solar before you turn it on. There are two routes:

• Notification (G98). For systems up to 3.68 kWp — you tell them after the install, no approval needed.
• Application (G99). For larger systems, you need approval before installation. This can take days or weeks.

Reputable installers handle DNO themselves and bake the wait into the timeline. Confirm they're doing this and that the time is included in their delivery date.

7. What monitoring do I get, and for how long?

Most modern systems come with an app that shows generation, self-consumption, and (for batteries) state of charge. A few questions:

• Does the monitoring portal stay free for life, or is there a subscription after year 1?
• Is the monitoring tied to the inverter brand (Solis, GivEnergy, Tesla, Enphase) — useful if you replace the inverter later?
• Does it report fault codes? Some only show generation, which makes diagnosing problems slow.

8. What happens if a panel fails in year 7?

Hypothetical, but a fair test of how the installer thinks about after-sales:

• Who do I call — you or the panel manufacturer?
• Will you visit, or do I have to ship the panel?
• Is there a labour charge, or is replacement included?

Reputable installers have a clear answer. Vague answers ("the manufacturer covers it") are a sign that the installer's own role is fuzzy.

Related

• How much do solar panels cost in the UK?
• How long does a UK solar installation actually take?
• Find listed installers covering your postcode