Solar Panel Quote Red Flags: How to Spot a Bad Deal

The clearest warning sign is pressure to decide during the first visit. Common versions include:

• A discount that is only available if you sign today
• A claim that prices are about to rise or that a scheme is about to close
• A representative who stays for hours and will not leave a written quote
• A "manager's special" phoned through during the visit
• Reluctance to let you compare other quotes

Genuine prices do not usually disappear overnight. A reputable installer will leave a written, itemised quote and give you time to compare it with others.

If you sign a contract at home or online, the Consumer Contracts Regulations 2013 generally give you 14 days to cancel. That is a useful safety net, but it is better not to need it. If a sales visit feels pressured, the simplest response is to ask for the quote in writing and end the appointment.

The "today only" discount is often the giveaway. A price that drops by thousands of pounds when you hesitate was usually inflated to begin with.

The second red flag is a price far above the market. Government cost data for MCS-registered home installations in 2025/26 puts typical prices at roughly £1,550 to £1,950 per kW, with larger systems cheaper per kW.

To check any quote, divide the total price by the system size:

• £7,000 for a 4.3kW system is about £1,630 per kW, in line with the market
• £11,500 for a 4.3kW system is about £2,670 per kW, well above typical prices

A higher price can be justified by a battery, premium equipment, optimisers or difficult access, but the quote should say so clearly. Without such a reason, a price far above £2,200 per kW on a simple roof is worth questioning.

Be equally wary of prices far below the market. A complete installation at under £1,000 per kW is unusual, and the gap may be explained by low-quality equipment, missing items or costs added later.

Our guide to home solar panel costs sets out typical prices by system size.

A large deposit is one of the clearest signs of risk. If an installer stops trading between taking your money and fitting the system, an unprotected deposit can be lost.

Reputable installers usually ask for a modest deposit, often in the region of 10% to 25%, with the balance paid after installation and commissioning. Be cautious of:

• Requests for 50% or more before work starts
• Pressure to pay the full amount upfront
• Payment requested by bank transfer to a personal account
• No written confirmation of how your deposit is protected

Ask the installer how your deposit is protected. Many installers belong to a Trading Standards-approved consumer code, such as the Renewable Energy Consumer Code (RECC) or the Home Insulation and Energy Systems Contractors Scheme (HIES), which provide deposit protection and dispute resolution. Others provide protection through an approved insurance product.

Paying part of the cost by credit card can add protection too. Under section 75 of the Consumer Credit Act, the card provider can share liability for purchases between £100 and £30,000, even if only part of the cost is paid by card.

A trustworthy quote names the equipment you are buying. A quote that describes panels only as "Tier 1 high-efficiency panels" or the inverter as "premium hybrid inverter" leaves the installer free to fit whatever is cheapest on the day.

Each quote should state:

• Panels: the manufacturer, model, wattage and number
• Inverter: the make, model and rating
• Battery, if included: the make, model and usable capacity
• Mounting system: on-roof or in-roof, and the make if known
• Warranties: the length of each product warranty and the installer's workmanship guarantee

With named models you can check datasheets and warranty terms yourself, and compare quotes on equal terms.

"Tier 1" is a particularly common piece of vague wording. It refers to a manufacturer's standing with lenders and financiers rather than a quality certificate for a specific panel, so it tells you little on its own. Ask for the exact model instead.

Savings forecasts are where many quotes go wrong, sometimes by accident and sometimes deliberately. Watch for:

• Claims that solar will eliminate your bill: you will still buy electricity at night and in winter, and you will still pay the standing charge.
• Unrealistic self-consumption: a household out at work all day is unlikely to use 80% of its solar output without a battery. Typical figures without a battery are 30% to 50%.
• The best export rate in the market: savings calculated using an export rate that requires switching to a particular supplier, or that is only offered with that supplier's own installations.
• Steep price inflation: forecasts that assume electricity prices rise sharply every year for 25 years.
• Payback claims under six years for a typical solar-only system, which are rare at current prices.

Ask how each figure was calculated, and recalculate it with your own annual use, a realistic self-consumption figure and the export tariff you would actually choose. Under Ofgem's price cap from 1 October 2026, electricity costs an average of 26.32p per kWh.

The red flag that costs households the most is often missing certification. Without MCS certification, a home solar system is generally not eligible for Smart Export Guarantee payments, which can be worth £100 to £300 a year or more. MCS certification can also matter to mortgage lenders and insurers.

Before signing, check:

• MCS certification: search the installer's name on the MCS website. Being "MCS-approved products" is not the same as being an MCS-certified installer.
• Electrical competence: the installer should be able to self-certify the electrical work through a scheme such as NICEIC or NAPIT, or arrange building control sign-off.
• Consumer protection: which consumer code or financial protection scheme covers your deposit and workmanship guarantee.
• Insurance-backed workmanship warranty: so the guarantee survives if the installer stops trading.

Ask to see evidence rather than taking claims on trust. A reputable installer will provide certificate numbers and scheme details without hesitation.

Solar finance can make an installation affordable, but it is also where some of the most expensive mistakes happen. Warning signs include:

• A monthly payment presented without the total amount payable
• Finance offered only at the end of a long sales visit
• Claims that the solar savings will cover the monthly repayments, without evidence
• Interest rates not stated clearly in writing
• Pressure to sign the finance agreement the same day

Any consumer credit agreement must show the APR and total amount payable, and most regulated credit agreements give you a 14-day right to withdraw. Compare the finance against other options, such as a personal loan or savings, before deciding.

Also check whether the finance is linked to the installation, because linked credit can give you additional rights if something goes wrong. If in doubt, take time to read the agreement and seek independent guidance before committing. The cheapest finance option is often not the one offered on the doorstep.

Some poor deals are not obviously expensive but include equipment that adds little value. Be cautious of:

• Oversized batteries: a battery larger than your evening use will rarely fill, adding cost without matching savings.
• Optimisers on unshaded roofs: useful where shading or multiple roof faces are involved, but often unnecessary on a simple south-facing roof.
• Expensive monitoring subscriptions: most inverters include free monitoring apps.
• Bundled extras of uncertain value: such as voltage optimisers, which typically offer little benefit in homes already supplied at normal voltages.
• Systems far larger than your roof or usage justifies: extra panels can be worthwhile, but not if they mainly export at a low rate.

Ask each installer to price optional extras separately, so you can see the cost of the core system and judge each addition on its merits.

Our guides to how many panels you need and solar and battery costs help you decide what size makes sense.

A competent installer will usually survey your roof, consumer unit and electrical supply before giving a final price, either in person or using detailed photos and satellite imagery followed by a site visit. Be wary of:

• A firm price given over the phone without any survey
• No questions about your electricity use or when you are at home
• No mention of shading from chimneys, trees or neighbouring buildings
• No discussion of the grid notification or any export limit
• No explanation of where the inverter, battery or isolators will go

The survey is also where the installer should check roof condition. Panels last 25 years or more, so if your roof will need work within a few years, a good installer will say so rather than fitting panels that will have to come off again.

A short, rushed visit focused on signing rather than understanding your home is a warning sign in itself. A good survey answers questions about your home before it asks for your signature.

Before you sign with any installer, run through these checks:

1. Get three written, itemised quotes and compare them on price per kW
2. Confirm the installer is MCS-certified on the MCS website
3. Ask which consumer code or financial protection scheme covers your deposit and workmanship
4. Check the exact panel, inverter and battery models and their warranties
5. Recalculate the savings using your own usage and a realistic export tariff
6. Check independent reviews and ask for local references
7. Confirm the deposit amount, payment stages and cancellation rights in writing
8. Take your time, and never sign during a first visit under pressure

A good installer will welcome these questions. One that becomes evasive or impatient has told you what you need to know.

Our guides to home solar panel costs and export tariffs help you check prices and savings. When you are ready, compare quotes from up to three MCS-certified installers.