Your MCS Certificate and Installation Handover Pack

When a certified installer finishes a solar array, a heat pump or another small-scale renewable installation at your home, the job is not complete until the paperwork exists. The MCS certificate is the formal record that the installation was carried out to the Microgeneration Certification Scheme's standards by a certified installer, and it is the document that grant schemes, export tariffs and future buyers of your home will ask to see. Your installer must register the installation on the MCS Installation Database no later than 10 working days after commissioning, and the certificate itself should reach you within 14 days¹.

Alongside the certificate sits the handover pack: the bundle of manuals, warranties, safety guidance and servicing schedules your installer must give you once the work is done². This page explains what each document is, what it proves, what to do if it never arrives or contains errors, and how the complaints process works if the installation itself falls short.

What the document shows and who issues it

The Microgeneration Certification Scheme is an independent certification scheme for microgeneration installation companies and products. Its roles include setting and maintaining technical standards for installations and products, certifying installers and products against those standards, and issuing MCS certificates for completed eligible installations⁸. It also assists certification bodies in reviewing and addressing cases and consumer issues relating to installers or products⁸. The scheme aims to ensure consistent standards and to give consumers confidence in what they are buying⁴.

What the certificate proves is narrower than many householders assume. It confirms that the installer was MCS certified for the technology they installed when they entered into a contract with you⁹, and that the installation was carried out under those standards. It does not confirm that the installer still holds certification today, nor that every aspect of the job met your expectations, only that it met the scheme's requirements at the point of commissioning.

Behind your installer stands a certification body: an independent organisation responsible for certifying and monitoring installers to make sure they meet MCS standards⁶. The certificate is generated through the MCS Installation Database by the installer, not hand-written by an engineer, which is why errors usually come down to data entry rather than the physical work. For the household pursuing energy independence, the certificate is the piece of paper that proves your generation or heating kit counts as properly installed in the eyes of government schemes, suppliers and buyers. More on what MCS certified installers must actually demonstrate appears on its own page.

Receiving your certificate: 10 working days after completion

The clock starts at commissioning, the point at which the installer finishes setting up and testing the system and declares it operational. Scheme rules require the installation to be registered by the MCS contractor on the MCS Installation Database no later than 10 working days after commissioning, with an MCS certificate generated, and the commissioning certification is to be issued to the client within 14 days of commissioning¹. The now-closed Domestic RHI applied a similar rule: installers needed to issue a certificate for an installation within 14 days of commissioning³.

If your certificate has not appeared within that window, the first step is to ask the installer directly, since the obligation sits with them rather than with MCS. A short delay is usually an administrative matter, but a certificate that never arrives can signal that the installation was never registered, which matters immediately if you are claiming a grant: the Boiler Upgrade Scheme voucher redemption application requires the MCS installation certificate number, along with the installer's BUS account ID and the unique voucher ID¹⁰. Without a certificate number, the grant cannot be paid.

The MCS certificate is a separate document from the building regulations paperwork, which runs on its own timetable. Where work is notified through a competent person scheme, the occupier is given a certificate confirming the work complies within 30 days of completion in Wales¹¹, and in England a building regulations compliance certificate is issued within 8 weeks of completion¹². A full plans application also produces a completion certificate within 8 weeks of the building work, provided it complies¹⁴.

Details entered on the certificate

The MCS is defined in official guidance as a certification scheme for microgeneration installation companies and products¹⁵, and the certificate is the installation-level record of that scheme. It covers small-scale renewable technologies such as solar photovoltaic panels, biomass, wind, heat pumps and heat products¹⁶. The certificate records the installation details, the certified installer, the technology fitted and the commissioning date, and it carries a unique certificate number that schemes use to verify the job.

For heat pump installations, metering information must be added to the MCS certificate¹⁷, so a heat pump certificate should carry more than the basic installation record. Where a Boiler Upgrade Scheme application covers a cascade system, only one MCS certificate should be generated in respect of that application¹⁸. The certificate number is not a formality: Ofgem's installer guidance for the Boiler Upgrade Scheme lists the MCS installation certificate number among the information required to redeem a voucher¹⁰, and the scheme's audit evidence includes copies of the MCS certificate¹⁹. Treat the certificate number the way you treat a passport number: record it, keep the original safe, and expect to be asked for it whenever the installation interacts with a scheme, a supplier or a conveyancer.

The certificate's value: funding, export tariffs and selling your home

MCS certification is a requirement for accessing many UK government incentives and is a route to many consumer grants and incentives²⁰. The practical effect is that without a certificate, most of the financial support attached to home energy installations is closed to you.

• Boiler Upgrade Scheme. The scheme is installer-led: installers who are MCS certified can apply for and redeem Boiler Upgrade Scheme vouchers on behalf of property owners⁸, and all BUS installations must be carried out by MCS-certified installers²¹.
• Smart Export Guarantee. For solar PV, wind and micro-CHP installations up to 50kW, presenting an MCS certificate or equivalent is the certification requirement²².
• Warm Homes: Local Grant. MCS certification is required for low carbon heating measures, with the exception of high heat retention storage heaters covered by PAS 2030²³.
• Home Energy Scotland Grant and Loan. Installations must be MCS certified to qualify for the funding²⁴.
• ECO4 and ECO4 Flex. Measures should be installed by or under the responsibility of a TrustMark registered installer with a relevant certificate of lodgement, covering measures certified under MCS²⁵, and MCS certification features in the flex referral routes used by local authorities¹⁶.

The certificate also matters when you sell. A buyer's solicitor will ask for evidence that the generation or heating system was properly installed, and an MCS certificate is the cleanest answer. Under the Domestic RHI, eligibility required a renewable heating system to be issued with an MCS certificate by the installer, and certificates could only be issued for systems using an MCS certified product¹⁷; that legacy means a certificate question can surface years after the installation. The wider picture of installer requirements for grants is covered separately.

Handover documents required at completion

The certificate is one document. The handover pack is the bundle that arrives with it, and MCS certified installers are required to provide it once the installation is complete. As a minimum it will contain:

• a list of key parts
• health and safety guidance
• a recommended servicing and maintenance schedule
• the manufacturer's instruction manuals
• all relevant guarantees and warranties²

The handover documentation is where the practical running of the system lives: how to operate it, what the safety rules are, when it needs servicing and what the warranties cover. Where a Metering and Monitoring Service Package is fitted, it must be installed by an MCS certified installer under a signed agreement meeting specific requirements, with a continuing advice service²⁶, so the aftercare arrangements form part of the certified installation rather than an optional extra.

Two limits are worth stating plainly. First, MCS specifies handover documentation but not the quality of verbal explanation, household understanding, structured follow-up or ongoing support²⁷. A compliant handover pack can still be handed over with barely a word of explanation, so the burden of reading it falls on the household. Second, the documentation is only as good as the installer who compiled it: if a guarantee is missing or a manual is for the wrong model, that is an installer failing, and it is one the complaints process can address. The detail of what belongs in the handover documentation has its own page on the MCS handover pack, and the warranties within it are covered under workmanship warranties and aftercare.

What MCS covers and what falls outside its scope

This is the section to read before treating a certificate as a promise of performance. MCS requires installers to provide a design-stage prediction of system efficiency, not to verify actual performance²⁷. The estimated annual generation figure on your certificate is a modelled number produced at design stage, not a measured one, and MCS does not require remediation of systems that are underperforming relative to their design²⁷. If your heat pump or solar array produces less than the estimate, the certificate does not by itself entitle you to a fix.

The same report notes that weather compensation is not mandatory under current MCS requirements, and third party non-modulating controls are not prohibited²⁷. In other words, the scheme sets a floor of standards, not a ceiling of best practice, and two MCS certified installations can perform quite differently while both being fully compliant.

On the product side, MCS product certification is described as a mark of quality that ensures compliance with UK regulations²⁸. The product audit behind it consists of a review of technical data files, a review of end of line tests in line with the quality plan, and a review of product testing evidence²⁸. That is a documentary and manufacturing audit of the product, not a test of the unit fitted in the home. MCS sets the standards a certified installer and the products they use are expected to meet²⁰, and for most households that expectation is a reasonable baseline, but the gap between a design-stage estimate and real output is one the household monitors. The page on performance estimates and savings claims explains how to read the numbers an installer quotes.

When amendments are allowed and when they are refused

Certificates get things wrong: a mistyped address, a wrong meter point number, a commissioning date entered incorrectly. The rules on correction are strict in both directions.

Changes to an MCS certificate are not permitted if the details were correct at the time of commissioning²⁹. The commissioning date may only be changed where there is clear evidence that the date was entered incorrectly by the installer²⁹. Subsequent changes to an installation do not require an amendment to the MCS certificate²⁹, so adding panels or swapping a component later does not rewrite history, and under the Feed-in Tariff, licensees were not expected to request that the MCS certificate be updated for post-entry alterations that made the certification outdated³⁰.

Where information in a certificate is genuinely incorrect, it should be corrected regardless of the length of time since the original certificate was issued³⁰. The electricity supplier can request in writing that an incorrect MPAN is updated³⁰. For a site address change, suitable evidence includes an invoice from the MCS certified company showing the correct address, or written confirmation from a third party such as a licensee³⁰. Where an extension is registered, if an MCS installer has carried out the works and a new certificate is issued, the new certificate should be used to register the extension; if no new certificate is issued, the original certificate number should be used³⁰.

One protection sits on the contract side rather than the certificate: if a change to your installation contract is significant, covering product specifications, design, cost, system performance estimates or timescales, you must be given the choice to continue with the new contract or to cancel without further cost, obligation or liability, with a refund of any deposit or pre-payment². And where an installer has entered wrong details, the consequences can reach beyond the paperwork: enforcement action in some cases can include suspension or removal of MCS certification⁵.

Vetting an installer and confirming a certificate

Before signing anything, official guidance is to use the government-endorsed Microgeneration Certification Scheme to find certified installers and to get at least three quotes from reputable installers³¹. Checking the installer's certification before the work, rather than discovering a gap afterwards, avoids the hardest problem of all, an installation that can never be certified retrospectively.

After the installation, MCS itself may contact you for a short, routine verification on behalf of Ofgem, either via email or by phone on 0333 103 8198⁷. Property owners contacted for these MCS checks should aim to respond within seven days¹⁰. For anything else, you can contact MCS through the mcscertified.com website or by calling 0333 103 8130⁷. These calls are verification, not sales, and a caller from these numbers asking you to buy something is not performing an MCS function.

Historically, a requirement of companies wanting to gain MCS certification was membership of a CTSI Approved Consumer Code of Practice scheme, such as the Renewable Energy Consumer Code³². That structure has changed under the redeveloped installer Scheme, covered below, so check which arrangement applies to your installer rather than assuming the old rules. The practical habit worth keeping is the same in either case: verify the certification, note the certificate number when it arrives, and keep the handover pack with the house documents.

How to complain: timescales and when ADR is used

For MCS certified installations, the complaint window is no more than two years after the date the system was commissioned⁴. That clock is firm, so a fault noticed at month twenty should not be left to drift.

The route runs in a fixed order. First, contact your installer: MCS is your single point of contact for complaints about MCS certified installers or installations, but only after an issue is raised with your installer first⁹. The installer must acknowledge a complaint within two working days and respond effectively⁵, and must give clear information on how to contact them with questions, concerns or complaints⁵. If you are unhappy with the installer's response and have not been through alternative dispute resolution, you can then go to MCS⁹.

MCS will consider complaints about system performance and design, quality of work, incomplete installation, delayed installation, commissioning and handover, installer conduct, damage to property, mis-selling, contractual issues, issues with the product, and breaches of the Customer Commitment⁹. Complaints can be raised by completing an online form, sending an email to mcscomplaints@mcscertified.com, by post, by phone or by live chat⁶. MCS will acknowledge your complaint within five working days⁶. To help, MCS will need details of what went wrong, photographic evidence, supporting documents, and your willingness to engage and allow the installer access to remediate⁶. Details of the complaint are shared with the installer, their certification body and, if applicable, their consumer code⁵.

If the MCS complaints process ends without a resolution you accept, alternative dispute resolution may follow. The conditions are: you have completed the MCS complaints process and remain dissatisfied, or you or the installer disagree with the proposed resolution, or the complaint has not been resolved within 12 weeks, or the contract is under the redeveloped installer Scheme, or the original Scheme contract was entered into on or after 1 January 2025 and the installer agrees in writing to engage in ADR⁶. Certified installers are required to take part in ADR with MCS's provider if a resolution cannot be reached through the MCS complaints process². The general escalation path is covered on the page about complaining about an installer.

The revamped installer Scheme and its impact on households

MCS has replaced the requirement for contractors to be members of a Chartered Trading Standards Institute approved consumer code with its own Customer Commitment³³. That is the single biggest structural change for households: consumer protection that previously sat with bodies such as RECC now sits within MCS's own framework, in force from 1 January 2025².

The Customer Commitment sets out what a certified installer must do, and much of this page is built from it: providing the handover pack, acknowledging complaints within two working days, giving clear contact information for questions and complaints, signposting customers to the MCS complaints process if they are unhappy with the outcome, and taking part in ADR where the complaints process does not resolve the matter². Under the redeveloped Scheme, MCS manages complaints in-house and provides alternative dispute resolution where the parties cannot reach a resolution, with the ADR eligibility conditions set out above⁶.

For a household, the practical consequences are threefold. The document trail is unchanged: the certificate, the 10 working day registration deadline and the handover pack remain the fixed points of a compliant installation¹. The complaints route is simpler, with MCS as the single point of contact rather than a scheme split between a certification body and a separate consumer code⁹. And the protections are MCS's own to enforce, with suspension or removal of certification among the sanctions for installers who breach them⁵. What the scheme still cannot do is guarantee performance: the design-stage estimate, not verified output, remains what the certificate records²⁷, so the household's own monitoring of how the system actually behaves is the final layer of protection.