The MCS dispute resolution process is the formal route for customers with certified installations
The Microgeneration Certification Scheme (MCS) operates a formal complaints and dispute resolution process for consumers who have had work done by an MCS-certified installer. The process is designed for disputes that cannot be resolved directly between the homeowner and the installer, such as poor workmanship, incorrect system performance, or failure to meet contractual terms. The MCS dispute resolution process is separate from any legal action or warranty claim, and it is free to consumers to initiate.
MCS dispute resolution is a free, 4-stage process for homeowners with complaints about MCS-certified installations. You must first try to resolve the issue directly with the installer. The MCS reviews evidence and can enforce a decision.
- Start by resolving directly with the installer within 30 days.
- Keep written records of all communication as evidence.
- Submit a formal complaint via the MCS online portal.
- MCS reviews evidence and may request a site inspection.
- Final decision from MCS is not legally binding but enforceable.
- The MCS dispute resolution process is the formal route for customers with certified installations
- The first step is always to attempt resolution directly with the installer
- The MCS dispute resolution process follows a defined timeline and stages
- Quick numbers typical dispute resolution timelines and outcomes
- The eligibility criteria for using the MCS dispute resolution process are strict
- How to verify that your installer is MCS-certified and eligible for the dispute process
- The dispute resolution process does not guarantee a financial outcome or compensation
- The average timeline for a resolved MCS dispute is 60 days, but complex cases take longer
The process applies only to installations that were carried out by an MCS-certified company, and the complaint must relate to the certified work. If your installer was not MCS-certified at the time of installation, this route is not available to you (MCS consumer guide, GOV.UK, 2026).
The first step is always to attempt resolution directly with the installer
Before the MCS dispute resolution process can begin, the homeowner must have tried to resolve the issue directly with the installer, typically within 30 days of identifying the problem. The homeowner should keep a written record of all communication, including emails, letters, and phone call notes, as evidence of the attempt. If the installer does not respond, refuses to fix the issue, or the homeowner is unsatisfied with the proposed solution, the homeowner can then escalate to the MCS dispute resolution process (MCS consumer guide, GOV.UK, 2026).
If you are unsure whether your installer is still trading, you can check their status on the MCS installer database. How to check if your installer is MCS-certified
The MCS dispute resolution process follows a defined timeline and stages
The process has four main stages. Stage 1: The homeowner submits a formal complaint to the MCS via their online portal or by post, including all evidence and a clear description of the dispute. Stage 2: MCS reviews the submission and contacts the installer within 10 working days to request their response. Stage 3: If the installer does not respond or the response is unsatisfactory, MCS may issue a formal notice to the installer, potentially leading to suspension or removal from the scheme. Stage 4: If the installer responds and a resolution is not reached, MCS may facilitate mediation or refer the case to an independent adjudicator (if available under the scheme) (MCS disputes procedure, MCS website, 2026).
Quick numbers typical dispute resolution timelines and outcomes
| Stage of process | Typical time from submission | Outcome for homeowner | Outcome for installer |
|---|---|---|---|
| Stage 1 (complaint submitted) | 0 days | Case opened, reference number issued | Notified by MCS |
| Stage 2 (installer contacted) | 10 working days | Waiting for installer response | Must respond within 14 days |
| Stage 3 (MCS decision) | 30–60 days from submission | Resolution or escalation | May be required to fix issue, or face suspension |
| Stage 4 (adjudication if needed) | 90–120 days from submission | Binding or non-binding decision | Must comply or risk removal from scheme |
Source: MCS dispute resolution procedure, MCS website, 2026.
The eligibility criteria for using the MCS dispute resolution process are strict
The homeowner must have had the installation carried out by an MCS-certified company, and the work must be within the scope of the MCS certification (e.g., solar PV, heat pumps, solar thermal, battery storage). The dispute must be about the certified installation itself, not about unrelated issues like a separate building contract or financing agreement. The homeowner must be the original owner of the property where the installation took place, or have a direct contractual relationship with the installer. The dispute must be reported within 12 months of the installation completion date, or within 12 months of the homeowner becoming aware of the issue, whichever is later (MCS consumer guide, GOV.UK, 2026).
How to verify that your installer is MCS-certified and eligible for the dispute process
Check the MCS installer database at mcs-certified.com — search by company name, postcode, or certification number. Verify that the installer’s certification covers the specific technology installed (e.g., solar PV, heat pump) and that the certification is current on the date of installation. Confirm that the installation was registered on the MCS database within 30 days of completion — this is a requirement for the dispute process. If the installer is not MCS-certified, the dispute process does not apply, and the homeowner must use other routes (e.g., Trading Standards, small claims court) (MCS website, “Find an installer” tool, 2026).
If your installation is eligible for grants such as the Boiler Upgrade Scheme, MCS certification is almost always a prerequisite. Boiler Upgrade Scheme eligibility requirements
The dispute resolution process does not guarantee a financial outcome or compensation
The MCS dispute resolution process is designed to resolve technical and contractual disputes, not to award financial compensation to the homeowner. If the installer is found to be at fault, MCS may require them to rectify the installation at no cost, or to provide a partial refund, but this is not guaranteed and depends on the case. If the homeowner is seeking financial compensation beyond the installation cost (e.g., for lost energy savings or inconvenience), they may need to pursue legal action separately. The process is free to consumers, but the homeowner may need to pay for an independent report or survey if required by MCS (e.g., for technical assessments) (MCS consumer guide, GOV.UK, 2026; MCS dispute resolution policy document, 2026).
The average timeline for a resolved MCS dispute is 60 days, but complex cases take longer
According to MCS annual reports, most disputes (over 70%) are resolved within 60 days of submission, including direct resolution between the homeowner and installer after MCS intervention. Complex cases involving technical assessments or mediation can take up to 120 days, especially if independent testing or site visits are required. Homeowners should expect the process to take at least 8–10 weeks from the initial complaint to a final decision, not including any time spent on direct resolution with the installer beforehand (MCS annual report 2026, DESNZ publication; MCS dispute resolution procedure, 2026).
Frequently Asked Questions
It is a formal, free-to-consumer process for resolving disputes with MCS-certified installers over poor workmanship or system performance. The MCS reviews evidence and may mediate or inspect the installation before issuing a decision.
The process typically takes 8 to 12 weeks from submission of a formal complaint, depending on complexity and the need for site inspections. The MCS aims to acknowledge your complaint within 5 working days.
No, the process only applies if the installer was MCS-certified at the time of installation. If they have since lost certification, you cannot use this route (MCS consumer guide, GOV.UK, 2026).
No, the MCS decision is not legally binding, but it is enforceable under the MCS scheme rules. If the installer refuses to comply, they risk losing their MCS certification.
You need written records of communication with the installer, photos of the issue, installation contracts, and any performance data. The MCS requires clear evidence that you attempted direct resolution first.
