Your MCS Certificate and Installation Handover Pack

The MCS certificate is the document that records that a specific microgeneration installation at a specific address was carried out by an MCS certified installer using MCS certified products. MCS itself is described by Ofgem as an independent certification scheme for microgeneration installation companies and products, whose roles include setting and maintaining technical standards, certifying installers and products against them, and issuing MCS certificates for completed eligible installations¹. For a household, the certificate is the key that unlocks grants, export payments and, later, proof to a buyer or a surveyor that the solar array, heat pump or battery on the property was installed to a recognised standard².

The certificate should reach the householder within 10 working days of completion. MCS states this consistently across its consumer pages for heat pumps, solar heating, biomass, battery storage, small wind and micro-CHP³. Separately, the installer must produce a handover pack at completion: a list of the system's key parts, health and safety guidance, a recommended servicing and maintenance schedule, the manufacturer's instruction manuals, all relevant guarantees and warranties, and a copy of the MCS Customer Commitment⁵.

MCS is a voluntary certification scheme in the sector⁶. Nothing compels an installer to be certified, and nothing compels a householder to use one. What certification changes is access: without it, funding, export tariffs and much of the redress machinery are closed off. The certificate is also a design-stage record, not a measured one, and that distinction runs through the rest of this page.

What the certificate proves, and who raises it

The certificate is, in MCS's own words, a record that an installation "has been done by a certified installer using certified products"². It names the MCS certified installers that carried out the work, and it is the raw material for the MCS Installations Database, which is built from the installation certificates raised by certified installers for each system they have delivered⁶.

Responsibility sits squarely with the installation company. Under the Renewable Energy Consumer Code, the MCS contractor that signs the contract with the consumer is responsible at all times for fulfilling it and must create the MCS certificate on its own MCS user account¹². Certification under the MCS installer standards means the business has the ability and expertise to fit, test and commission an energy generator or battery storage unit in compliance with ISO 17065¹². MCS describes itself as the UK's quality mark for small-scale renewables such as heat pumps⁴, and local authority guidance points householders to the government-endorsed scheme to find certified installers¹³.

Each installer is monitored by a certification body: independent organisations responsible for certifying and monitoring installers to ensure they meet MCS standards¹⁰. So three parties stand behind a certificate: the installer that raised it, the certification body that audits the installer, and MCS that sets the standards and holds the database. More detail on the underlying rules sits on the pages covering MCS certified installers and the MCS installation standards.

When your certificate arrives: 10 working days from completion

MCS states across its consumer technology pages, for ground and water source heat pumps, biomass, solar heating, battery storage, small wind and micro-CHP alike, that "You will receive an MCS certificate within 10 working days of completion"⁴. That is the figure to hold an installer to.

Other timescales appear in scheme paperwork and they do not all match, because they were written for different purposes:

The 10 working day and 14 day figures are not in conflict so much as drawn from different documents: MCS's own consumer commitment to a 10 working day turnaround, and scheme rules that allowed 14 days from commissioning. Where a contract references a funded scheme, the scheme's deadline is the contractual one. The building control certificates on the same table are separate documents on a separate clock and do not replace the MCS paperwork. Where electrical work has been carried out, a BS 7671 certificate should be provided directly by the installer after the work is completed, entitled either an Electrical Installation Certificate or a Minor Electrical Installation Works Certificate²⁰.

What is recorded on the certificate

Certificate content is driven by the data the installer enters at commissioning. Address and MPAN details are required for the installation location²¹. The names of the MCS certified installers that carried out the work appear on the certificate⁶. The overall cost of the installation is captured and cannot be edited once the certificate has been created²¹. For heat pump installations claiming metering-related support, metering information must be added to the MCS certificate²².

The certificate also carries the performance estimate produced at design stage. MCS requires installers to provide a design-stage prediction of system efficiency, rather than verifying actual performance²³. That estimate is what grant and export bodies read, and what a household will later compare against its bills. It is a modelled figure, not a measurement, and the gap between the two is the single most common source of disappointment after a renewables install. The rules on what such an estimate must contain are set out on the page about performance estimates in quotes.

Why the certificate matters: grants, export payments and resale

MCS certification is a requirement for accessing many UK government incentives, and MCS presents it as a route to consumer grants and incentives generally²⁴. The specifics differ by scheme and by nation.

• Boiler Upgrade Scheme (England and Wales): installer-led. Installers who are MCS certified apply for and redeem vouchers on behalf of property owners¹. All BUS installations must be carried out by MCS certified installers, who must also be certified to install heat pumps or biomass boilers²⁵. Redemption requires the MCS installation certificate number, the BUS installer account ID, the unique voucher ID and, where applicable, a biomass emissions certificate²⁶. Copies of the MCS certificate form part of the audit evidence²⁷.
• Domestic RHI (closed to new applicants): a renewable heating system had to be issued with an MCS certificate by the installer, and certificates could only be issued for systems using an MCS certified product²².
• Smart Export Guarantee: for solar PV, wind and micro-CHP installations up to 50kW, an SEG application means presenting an MCS certificate or equivalent²⁸.
• 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 2030²⁹.
• Scotland: Home Energy Scotland Grant and Loan funding requires installations to be MCS certified to qualify³⁰.
• ECO4: measures should be installed by or under the responsibility of a TrustMark registered installer with a relevant certificate of lodgement, for measures covered by PAS and schemes including MCS³¹.

Independent guidance is blunt about the consequences of not having one: without MCS certification, homeowners may be unable to access SEG payments, qualify for certain grants, or demonstrate compliance properly³². Households cannot apply for these grants themselves, since certification is what allows the installer to apply on the household's behalf³³.

In Scotland, an MCS Certification Fund supports installer certification on heat pumps, paying 75% of certification fees up to a maximum of £1,000³⁴. That is a grant to installers rather than households, but it bears on how many certified firms a rural Scottish household can reach.

For resale, the certificate is the durable artefact. Warranties expire and installers close, but the certificate and its database entry remain the evidence that the equipment was fitted by a certified business to a defined standard.

The handover pack: what must be given on completion

The handover pack is distinct from the certificate and broader. The MCS Customer Commitment sets the minimum: the installer must provide a handover pack once the installation is complete containing, as a minimum, a list of key parts, health and safety guidance, a recommended servicing and maintenance schedule, the manufacturer's instruction manuals, and all relevant guarantees and warranties⁵. MCS consumer pages add a copy of the MCS Customer Commitment itself, which outlines the responsibilities certified installers have towards their customer and explains the consumer's rights³.

Consumer code rules fold the certificate into the same bundle. Under the RECC code, handover documents must, where relevant, also include the MCS certificate, the compliance certificate and the invoice for payments received¹².

An independent scheme body puts it simply: following any work done under MCS, the householder should be left with a handover pack with a number of specific contents²⁰.

What MCS certifies, and what it does not check

MCS is a quality mark that shows a product, or an installation including one or more MCS certificated products, meets requirements defined in the MCS standards³⁵. Product certification rests on an assessment of evidence that the product complies with the relevant MCS Product Standard, a review of technical documentation, and a product audit covering technical data files, end of line tests in line with the quality plan, and product testing evidence³⁶. The product standards themselves set out performance test methods and the criteria a certified product must meet³⁶. Certification bodies describe the route as testing, audit and certification.

What the certificate does not do is confirm how the system performs in the house. MCS requires a design-stage prediction of system efficiency, not verification of actual performance, and it does not require remediation of systems that are underperforming relative to their design²³. The same analysis notes that weather compensation is not mandatory under current MCS requirements and that third party non-modulating controls are not prohibited²³. A certificate, therefore, is evidence of process compliance at a point in time. It is not a guarantee of a seasonal performance factor, a bill saving or a comfort outcome.

For a household pursuing energy independence, the practical reading is this: the certificate secures the money and the redress route, and the standards behind it reduce the chance of a badly designed system. It does not remove the household's dependence on the installer's design judgement, on the manufacturer remaining in business to honour product warranties, or on the grid and supplier arrangements that the export and grant payments run through.

When a certificate can be amended, and when it cannot

The governing rule from Ofgem's Feed-in Tariff guidance is narrow: "Changes to an MCS certificate are not permitted if the details were correct at the time of commissioning"³⁸. The commissioning date itself may only be changed where there is clear evidence that it was entered incorrectly by the installer³⁸. Subsequent changes to an installation do not require an amendment to the certificate³⁸.

Genuine errors are a different matter. Ofgem guidance states that incorrect information within a certificate should be corrected regardless of the length of time since the original certificate was issued³⁹. Where an MPAN is wrong, the electricity supplier can request in writing that it be updated³⁹. Where a site address is wrong, acceptable evidence includes an invoice from the MCS certified company showing the correct address, or written confirmation from a third party such as a FIT licensee³⁹.

Where a system is later extended, the treatment depends on whether new certified work was done. 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 used³⁹. Where alterations after entry make the certification outdated, FIT licensees are not expected to request that the certificate be updated³⁹. For heat pump cascade systems under the Boiler Upgrade Scheme, only one MCS certificate should be generated in respect of a cascade application⁴⁰.

Two things are effectively fixed once the certificate exists: the overall cost of the installation cannot be edited after creation²¹, and the certificate names only the MCS certified installers that carried out the work⁶.

Where a change happens before completion, the Customer Commitment gives rights at contract stage: if a change is significant, the customer must be given the choice to continue with the new contract or cancel without further cost, obligation or liability and receive a refund of any deposit or pre-payment. Significant changes expressly include changes to product specifications, design, cost, system performance estimates and timescales⁵. See also installation contracts and cancellation rights.

Checking an installer and verifying a certificate

MCS states that an installer's status can be checked through its Find an Installer online tool or by contacting its Customer Support Helpdesk⁴¹. Local authority advice recommends using the government-endorsed scheme to find certified installers and getting at least three quotes from reputable installers¹³.

Verification also runs the other way. From May 2026, the MCS Customer Insights team began reaching out to a selection of customers with an MCS certified installation, to verify the MCS certificate and make sure the installation process was delivered to the customer's satisfaction⁴². MCS reported in September 2026 that it will be contacting every recipient of an MCS certified installation⁴³. Separately, MCS may contact a property owner for a short routine verification on behalf of Ofgem, by email or by phone on 0333 103 8198, and property owners should aim to respond within seven days where additional checks are requested⁴⁴.

More on pre-purchase checks sits on checking an installer before you sign and mis-selling and doorstep sales.

Complaints: the route, the clock and when ADR applies

The installer comes first. MCS describes itself as the single point of contact for complaints about MCS certified installers or installations, after an issue has been raised with the installer⁴⁶. Certified installers must give clear information on how to contact them with questions, concerns or complaints, must acknowledge a complaint within two working days and respond effectively, and must signpost customers to the MCS complaints process if they are unhappy with the outcome⁹.

The deadline is hard. For MCS certified installations, a complaint must be made no more than two years after the date that the system was commissioned⁸. A further condition is that the installer was MCS certified for the technology they installed when they entered into the contract⁴⁶.

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 a product, and breaches of the Customer Commitment⁴⁶. Complaints can be raised by online form, email to mcscomplaints@mcscertified.com, post, phone or live chat, and MCS acknowledges within five working days¹⁰. It asks for details of what went wrong, photographic evidence, supporting documents, and a willingness to engage and allow the installer access to remediate¹⁰. Details are shared with the installer, its certification body and the installer's consumer code where applicable⁹. Enforcement can, in some cases, include suspension or removal of MCS certification⁹. Installations that do not meet MCS standards can also be reported through the whistleblowing route, and MCS states that lessons learned are used to improve scheme oversight and maintain standards¹¹.

Alternative dispute resolution is the final stage. Certified installers must take part in ADR with the MCS provider if a resolution both parties agree on cannot be reached through the MCS complaints process⁹. ADR is available where the MCS complaints process has been completed and the customer remains dissatisfied, where customer and installer disagree with the proposed resolution, where the complaint has not been resolved within 12 weeks, where the contract falls under the redeveloped installer Scheme, or where an original Scheme contract dated on or after 1 January 2025 exists and the installer agrees in writing to engage in ADR¹⁰. Ofgem's older FIT guidance directed householders with an installation company complaint to contact both MCS and the Renewable Energy Consumer Code, and noted that an unresolved complaint can be taken to the MCS Administrator, who advises how to complain about an MCS installer⁴⁷. The routes are set out further on complaining about an installer and the Renewable Energy Consumer Code.

The redeveloped installer Scheme and what changes for households

MCS has rebuilt its installer Scheme with consumer protection at its centre⁴⁹. The redeveloped Scheme was reported as live in August 2026 and rolling out across the MCS installer base⁵⁰, described in July 2026 as being rolled out to thousands of businesses and as set to transform the consumer protection landscape in the UK⁴⁹. In September 2026 MCS reported that it now manages complaints in-house and provides alternative dispute resolution where parties cannot reach a resolution, and that certified installers use MCS certified products designed, tested and manufactured to industry-recognised standards⁴³. An installer transition phase is due to end on 31 March 2027, by which date all MCS certified installers must operate under the redeveloped Scheme.

One consequence for households concerns consumer codes. Government's November 2025 response on Boiler Upgrade Scheme amendments records that MCS have replaced the requirement for contractors to be members of a Chartered Trading Standards Institute approved consumer code with their own Customer Commitment⁵¹. Trading Standards' own code pages still describe membership of a CTSI Approved Consumer Code of Practice scheme as a requirement for companies wanting to gain MCS certification⁵². Where an installer is a code member, MCS shares complaint details with the code⁴⁶.

In practice, during the transition period a household should expect to see either arrangement referenced in a handover pack, and should note which one the contract names, because it determines where a complaint that MCS cannot resolve goes next. MCS also states that profits it makes fund the MCS Foundation's activities⁴⁵.