MCS certificate: what it is and why your solar panels need one

An MCS certificate is the record that your solar panels or battery were installed and commissioned by an MCS-certified installer, using MCS-certified products, to MCS standards. It is not a legal requirement for installing panels. But in Great Britain you need it, or an equivalent certification, to be paid for exported electricity under the Smart Export Guarantee, and the new Warm Homes loans require an MCS installation. Your installer creates the certificate after commissioning and sends it to you. If it is lost, ask the installer first; MCS can issue a copy for £36 if the installer is no longer certified or trading.

What MCS is

MCS stands for the Microgeneration Certification Scheme. It describes itself as the UK's quality mark for small-scale renewable technologies such as solar panels, batteries and heat pumps, with two roles: setting standards and providing consumer protection. It certifies both products and installers, and it runs the MCS Installation Database, where certified installers register each system they install. That registration is what produces your certificate.

MCS covers all four UK nations. You can have panels installed without it, but in Great Britain export payments depend on it, or on an equivalent certification, and the Warm Homes loans require it.

What the certificate shows

MCS says the certificate proves the installation was "designed, installed, and commissioned to industry-recognised standards". It records:

• the type and model of the technology installed;
• the installation company and its certification details;
• confirmation that the system complies with MCS standards;
• details about your installation, such as the address, the electricity supply number (MPAN) and the commissioning date;
• the system's capacity figures and product details, and the generation meter details.

MCS will only issue a certificate if the installation was commissioned by an MCS-certified installer, includes an MCS-certified product and was commissioned after 15 July 2009.

When you need it

The Smart Export Guarantee rules recognise schemes equivalent to MCS. Without an MCS certificate, Ofgem says your installation and installer should be accredited under EN 45011 or EN ISO/IEC 17065:2012, and your chosen supplier will tell you what it needs. See our Smart Export Guarantee guide and our Warm Homes Plan guide.

If you sell your home, keep the certificate with your property documents. A buyer who wants export payments will be asked for proof that the system is certified.

What an MCS installer must give you

These duties apply to every MCS-certified solar installer, whichever version of the scheme they are on.

Before you sign the contract, in writing:

• a performance estimate of the system's yearly output, worked out with the MCS method, including how much of that electricity you are likely to use at home;
• the manufacturers' datasheets for the panels, the inverter, any optimisers or microinverters and any battery;
• a drawing of the proposed panel layout;
• where shading reduces the estimate and the MCS method was used, the sun-path diagram behind that figure.

The estimate must carry MCS's standard warning that it is guidance for the first year only and "should not be considered as a guarantee of performance". If an installer won't provide these before you sign, treat it as a warning sign. Our guide to comparing solar quotes shows how to use them.

After the installation: a handover pack with the list of key components, the performance estimate, manuals, warranties and maintenance advice, and your MCS certificate. On MCS's original scheme, the installer must register the system on the MCS database within 10 working days of commissioning. On MCS's redeveloped scheme, you should receive the MCS certificate, any Building Regulations compliance certificate and proof that the electricity network operator was notified or approved the connection within 30 calendar days of completion.

Two versions of the MCS scheme in 2026

MCS is moving installers to a redeveloped scheme, with most moving over during 2026. For you, the changes that matter are:

• Consumer code membership is no longer mandatory. Consumer codes such as RECC and HIES set extra rules for their members; RECC's, for example, caps deposits at 25% and requires an insurance-backed workmanship guarantee of at least two years. Under the redeveloped scheme those rules apply only if your installer is a member, so check the code's own member list.
• MCS handles complaints centrally. Redeveloped-scheme installers must acknowledge a complaint within two working days, point you to the MCS complaints process if you are unhappy with their answer, and take part in MCS's alternative dispute resolution if that fails.
• A written Customer Commitment, given to you before you commit, covering clear quotes, fair deposits, realistic estimates and no pressure selling.
• The technical rules are the same. On the original scheme, solar installers work to MIS 3002 Issue 6.0, mandatory since 18 June 2026. On the redeveloped scheme, installation follows MIS 3002:2025 and the pre-sale information and performance estimate follow a separate standard, MCS 032:2025. MCS says the technical requirements have been restructured, not changed.

Ask any installer which version of the scheme they are on and whether they belong to RECC or HIES.

How to check an installer

Use MCS's Find an Installer search. You can search by company name or certification number, filter by technology and area, and see each installer's certification number and the technologies they are certified for. Check that the company quoting you is certified for solar PV, and for battery storage if a battery is included, and that the certification number on your quote matches.

Lost, missing or wrong certificate

Lost it?

Ask the installer that fitted your system for a copy. MCS will only issue a copy itself if the installer is no longer MCS-certified or no longer trading. In that case:

1. Fill in MCS's request form on its certificate queries page. Only the current owner of the system, or their legal representative, can ask.
2. Attach proof that you live at the address, such as a utility bill or bank statement less than three months old, a council tax letter less than 12 months old, or a photo driving licence.
3. Pay the admin fee of £30 plus VAT (£36) when MCS sends a payment request. It covers one copy with any number of corrections.
4. MCS sends the certificate within 10 working days of payment.

Not sure one exists?

Call the MCS helpdesk on 0333 103 8130 with the technology type and the full installation address, including the postcode. MCS will ask for proof that you live there.

Details wrong?

Corrections go through the installer first, then MCS on the same terms. For example, MCS asks for a full electricity bill showing the MPAN to correct the address or supply number, and a clear photo of a new generation meter after a meter change.

Never issued?

If a certified installer fitted MCS products but never registered the system, MCS says it cannot raise a new certificate for you. Go back to the installer, and use its complaints process and then MCS's if it does not put things right. Under the Consumer Rights Act, an installer must do the work with reasonable care and skill and keep to what it told you before you signed, including a promised MCS certificate. To avoid this, agree in the contract when you will receive the certificate, and chase it as soon as that date passes.

DIY and plug-in solar

A system you install yourself can't get an MCS certificate, because it must be commissioned by an MCS-certified installer. That rules out export payments for most DIY systems. Plug-in solar kits, allowed since 27 August 2026 within set limits, are set up without an installer, so they have no MCS installation certificate; don't count on export payments for one.

If you are planning a full rooftop system, our calculator gives an illustrative estimate of output and bill savings for homes in Great Britain, and installed systems carry 0% VAT until 31 March 2027.

Frequently asked questions

What does MCS stand for?

The Microgeneration Certification Scheme. It certifies small-scale renewable products, such as solar panels, batteries and heat pumps, and the companies that install them.

Do you need an MCS certificate for solar panels?

Not to install them. You need one, or an equivalent certification, to receive Smart Export Guarantee payments in Great Britain for systems up to 50 kW, and for a Warm Homes loan.

How do I get an MCS certificate?

Use an MCS-certified installer and MCS-certified products. The installer registers the finished system with MCS and sends you the certificate.

What does an MCS certificate look like?

It is a document that names the installer and its certification number, the installed technology and model, your installation address and commissioning date, and confirms compliance with MCS standards.

How much does a replacement MCS certificate cost?

Your installer can resend it. If the installer is no longer certified or trading, MCS charges £30 plus VAT (£36) for a copy.