How to Check a Solar Battery Installer Is MCS Certified

Short answer: search the installer's company name or MCS certification number on the official MCS "Find an installer" tool, and confirm that the listing covers battery storage, not just solar panels or heat pumps. If you want to use the Warm Homes Loan Scheme or the Local Grant, MCS certification is a requirement, not an extra. This page explains what MCS covers, how to check it step by step, what a written quote should show and which warning signs to take seriously. This site is an independent publisher: we are not an installer and are not MCS-certified, and we do not recommend installers. We checked the official pages on 8 October 2026.

What MCS is and what it covers

MCS describes itself as the UK's quality mark for renewable energy systems such as solar panels and heat pumps, and says certification applies to both installers and products (MCS consumer information). Its installer directory lets you search for installers certified for technologies including solar panels and battery storage (MCS Find an installer).

The government's own loan scheme rules describe MCS as the quality assurance and consumer protection organisation for small-scale renewables, covering installer competence, product and installation quality, financial protection products, complaints about workmanship and dispute escalation (Warm Homes Loan Scheme rules). Those rules say a battery must be an MCS-certified product installed by an MCS-certified installer to the relevant MCS standard. The Local Grant guidance names the battery standard as MIS 3012 (DESNZ guidance).

How to check an installer, step by step

1. Ask for the company's MCS certification number before you ask for a quote. A genuine installer will give it without fuss.
2. Search the MCS directory by name or number, or by technology and location (MCS directory). Check that the company name matches the one on the quote and the contract.
3. Check the technology. A company may be certified for solar panels but not for battery storage. The listing should show the technology you are buying.
4. Check the consumer code. MCS says installers work under consumer protection frameworks that require proper contracts and quotations. Ask which approved consumer code the company belongs to (for example RECC or HIES) and look the company up on that code's own website.
5. Ask what you will receive at handover. MCS describes an MCS Installations Database and certificate system and insurance-backed guarantee products (MCS consumer protection). Ask for the MCS certificate, the electrical installation certificate and the warranty documents, and ask who notifies your electricity network operator.

The directory proves certification, not quality. Read reviews on independent sites, and ask for a recent customer you can speak to.

What a written quote should show

A good quote lets you compare like with like. Look for:

• the battery make and model, and its usable capacity in kWh, not only the headline capacity (see sizing);
• the total price, with VAT shown separately. Installing a battery in a home is zero-rated until 31 March 2027, then 5%, but only where the same business supplies and installs it (HMRC Notice 708/6);
• what is included: scaffolding, consumer unit work, any backup wiring, monitoring app, commissioning;
• the deposit, the payment schedule and the cancellation terms;
• the warranty length and what it covers, including the inverter and who stands behind it if the installer stops trading;
• any grant or loan the quote assumes, in writing, with the name of the scheme and the lender.

Red flags

• No MCS number, or one that does not match the company name.
• "Free" battery offers that are not tied to a named scheme you can check. See is free solar battery storage real.
• Pressure to sign the same day or to pay a large deposit by bank transfer before any documents arrive.
• Guarantees about a grant. The Local Grant is decided by your council after you apply online, so no installer can guarantee an outcome. Our Local Grant guide explains the process.
• A quote with no model name, no capacity or no VAT line.
• Cold calls or messages claiming to be from the government or a scheme. Schemes do not work this way.

If something goes wrong

MCS describes a complaints route: raise it with the installer first, then escalate through the certification body (MCS). Keep the quote, contract, certificates and messages. For funding questions, see the funding overview, and use our eligibility check before you ask for quotes.

Frequently asked questions