Redeveloped MCS Installer Scheme: risk-based surveillance and your assessment

The Microgeneration Certification Scheme (MCS) is a nationally recognised quality assurance scheme for small-scale renewable energy installations, solar panels, solar heating, heat pumps, and battery storage. In 2025, MCS launched a redeveloped scheme to help support the rapid growth in demand for competent installers of these technologies.

The updated scheme focuses more on installation quality and protecting the consumer, and less on administrative requirements. In our previous blog, we introduced the changes and discussed the benefits for installers and consumers. Here, we look at the transition process in more detail, explain the new risk-based approach to surveillance, and discuss what you can expect for your business assessment under the new requirements.

Transitioning to the redeveloped scheme

NICEIC is now approved to deliver the redeveloped MCS Installer scheme, and we’ve begun transitioning existing certified installers in planned waves. This phased approach will continue over the coming months as we work to contact every installer.

All new applicants will automatically be assessed under the redeveloped scheme. If you already have an application in progress, our team will be in touch to guide you through the transition.

Whether you’re an existing installer or a new applicant, we’ll ask you a series of questions about your business, including:

• company structure
• trading status (limited company or sole trader)
• geographic spread of work
• named individuals in significant roles
• the scopes of work you’re certified, or seeking certification, for
• subcontractor arrangements.

Under the revised scheme, you’ll also have direct contact with MCS at the application point. Alongside your application to NICEIC, MCS will now do a series of back-office checks on your business, which will be repeated annually. These include checking:

• financial performance
• insurance status
• directors and persons with significant control
• information about your business in the public domain
• how you treat customers
• previous complaints and legal proceedings.
• MCS monitoring activities associated with the compliance of your installations.

New business scenarios

MCS has created four scenarios that consider the size and complexity of your business and its activities. The processes and controls you will be expected to demonstrate for your assessment will now be determined by these operating scenarios, which are outlined in Appendix A of the Installer Operating Requirements.

We’ll map your business into the appropriate scenario based on the number of your employees directly involved in MCS-related activities, use of subcontractors to deliver installation work, and spread of installation work across geographical regions. The scenarios are:

• Scenario A: sole trader, not using subcontractors to deliver installations and operating in a single geographical region.
• Scenario B: installer with more than one employee but less than 50 employees directly involved in MCS-related activities, not using subcontractors to deliver installations and operating in a single geographical region.
• Scenario C: installer with equal to or more than 50, but less than 250, employees directly involved in MCS-related activities OR an installer with less than 50 employees directly involved in MCS-related activities, and either using subcontractors (including as Technical Supervisors) to deliver installation work or operating in multiple geographical regions.
• Scenario D: installer with equal to or more than 250 employees directly involved in MCS-related activities OR an installer using subcontractors (including as Technical Supervisor) to deliver installation work and operating in multiple geographical regions.

For example, if you’re a sole trader with no subcontractors and only undertaking MCS installation work in the North West, you’d be in Scenario A. If you’re an installer using subcontractors to deliver installation work and operating in multiple geographical regions, you’d be in Scenario D.

These scenarios recognise bigger businesses and/or those with more complex operations will need more robust processes and controls to ensure delivery of a quality service. A table in Appendix A of the Installer Operating Requirements outlines the relevant process and control requirements against each scenario.

Our assessment of your service delivery will establish evidence of appropriate processes and controls that are aligned to these scenarios, and we will assess whether these have been effective via site-based assessments of a sample of your installations.

What does risk-based surveillance look like?

The new MCS Quality Risk Model is designed to improve the effectiveness of our surveillance by focusing resources on installers that pose a higher risk to compliance and quality.

As a certification body, we will now use a combination of information to determine the frequency of your site-based assessments using a risk calculation. This is based on factors including your business scenario, the number of installations you carry out, how long you have held certification, and the number and outcomes of previous assessments. For some businesses, this means we might not need to assess you every year, while for others we may be asking to see a few more installations each year.

The various risk factors have different percentage weightings and contribute to the overall risk score. Once we’ve calculated your risk profile (reduced/standard/enhanced) for each certified technology, we’ll place your business on:

• Reduced assessment frequency – an assessment every three years. An annual document submission is still required, and installers must be certified for over two years with two consecutive pass outcomes. Changes, such as to the Technical Supervisor or legal entity, will move you back to standard.
• Standard assessment frequency – annual assessment (based on certification date), with a minimum of one site per technology. All new installers will stay on standard assessment frequency (where no problems are identified) for the first two years, and installers carrying out over 100 installs annually will remain on the standard rate.
• Enhanced assessment frequency – annual assessment (based on certification date) and a minimum of five sites per technology. Installers with reassessment outcomes or a high number of major non-conformities will move to enhanced rate. If major non-conformities are found in the sample, an additional five sites will be assessed, this will continue until compliance can be demonstrated.

NICEIC can schedule additional assessments at any time based on evidence of non-compliance and/or significant changes to the size and complexity of your MCS-related activities.

What does the assessment process look like?

Another key new scheme document, Conformity Assessment Guidelines, provides certification bodies, including NICEIC, with guidance on how we should conduct assessments against the redeveloped scheme. This provides our framework for conducting compliance assessments using the MCS Assessment Criteria for the technology installed. These incorporate:

• checks to determine the presence and effective operation of your processes and controls
• installation checks specific to the requirements within the relevant MCS Installation Standard and Pre-sale Information and System Performance Estimate Standard, as well as compliance with BS 7671, planning regulations and building control regulations relevant to each technology you design and install.

You will still be required to show you are managing processes to deliver quality, but these now reflect requirements deemed appropriate for your operating scenario (Appendix A of the Installer Operating Requirements), removing the previous emphasis on paperwork and a formal quality management system.

Under the Installer Operating Requirements, to deliver quality installations, you need to operate processes and controls that ensure:

• maintenance of the competency of your staff and any subcontractors (including Technical Supervisors)
• compliance with the MCS Installation Standards, Pre-sale Information and System Performance Estimate Standards, and related industry standards associated with your installations
• customer satisfaction, including in managing customer feedback and complaints
• maintenance of effective business records for the delivery of installations.

The technical elements and expectations (technical truths) you need to meet for each technology during your site-based installation assessments have not changed. These are set out in a simplified set of documents, the MCS Installation Standards (MIS).

Assessment findings

When you’re looking at assessment findings, you’ll see some changes in terminology and practice. Previously, your assessment report will have listed ‘non-conformities’ and ‘observations’. These are now identified as:

• Major non-conformities: present a significant impact on system function, performance or efficiency (and in some cases present a safety risk to people and/or property/the installer’s ability to deliver the service).
• Minor non-conformities: present no or minimal impact on system function, performance or efficiency/the installer’s ability to deliver the service.

For each non-conformity raised during an assessment under the new scheme, you have to investigate and share details of the root cause, as well as provide evidence of corrective and preventive actions.

Determining adequate supervision

There have also been changes to supervision terminology and requirements. The previous term Technical Person has changed to Technical Supervisor (TS). This is still the person who takes overall responsibility for technical standards and quality on an installation, but that person (or persons) is now specifically named.

The Installer Operating Requirements state the number of TSs needs to be appropriate to the size and complexity of your MCS activities. You must also ensure all employees and subcontractors delivering installations are adequately supervised and be able to demonstrate how you have determined their supervision needs.

So, you need to establish both the appropriate number of TSs and the level of supervision they need to undertake during an installation. You also need to keep records to provide evidence of effective supervision.

MCS has produced a guidance document to help installers and their TSs identify a supervision approach that works for their circumstances and ensures a quality service. For contractors certified on our electrotechnical schemes, this process will already be familiar.

Moving forward

Once you’ve transitioned to the redeveloped MCS Installer Scheme, the certification process will settle into a yearly cycle, whereby you’ll receive an annual review of certification to confirm the size and complexity of your MCS-related work and identify any changes that might affect your certification.

This will involve completing a document submission request form sent by our Customer Services team. We’ll then input your replies, and other relevant data, into the risk calculation table and communicate your risk rating to you and to MCS. This will indicate whether you’re on standard, reduced or enhanced assessment frequency and, based on this, we’ll deliver the appropriate assessments.

We’re taking a phased approach to transitioning our certified installers to the redeveloped scheme, which means we can support every business through the process. If you’re an existing MCS installer or a potential new applicant and you have any questions or want to know more, please get in touch, or follow the links below.

More information

Read our previous blog on MCS:2025.

Check out our recent episode of The Wire covering the MCS changes and what they mean for your business.

Visit the MCS website for latest scheme updates and to access core documents.

Download the interactive MCS guide to moving to the redeveloped scheme.

Access our FAQs on the redeveloped scheme.