MIS 3002 is the MCS installation standard for solar PV systems. It governs how MCS-certified installers must design and install solar PV systems in order to issue a valid MCS certificate. The standard covers solar PV systems up to 50 kWp DC — the overwhelming majority of residential and small commercial work.
A valid MCS certificate is required for consumer access to the Smart Export Guarantee (SEG) and for most ECO4 and Warm Homes Plan routes. Without it, the installation is uncertified.
V6.0 was published 18 March 2026. The changes are targeted — they do not rewrite the whole standard. They concentrate on clause 5.5.5, which covers what an installer must document when there is no MCS 012-certified mounting system available for a specific installation.
Under V5.0 (previous version), clause 5.5.5 required a written statement that the installation met Building Regulations requirements. That statement was sufficient.
Under V6.0, that written statement is replaced by documented evidence of all of the following:
Software-generated calculations from tools such as PVSyst or PVSol do not satisfy the structural requirement unless reviewed and signed by a qualified structural engineer.
V6.0 formalises structural engineer requirements in section 5.9.6. A qualified structural engineer is now mandatory for:
For flat roof ballasted arrays, section 5.9.13(h) is an absolute requirement: a qualified structural engineer must assess the imposed load from the array and ballast on the roof structure. No installer discretion applies to this case.
For most routine pitched-roof installations using a fully MCS 012-certified racking product, clause 5.5.5 is not engaged at all. If your mounting system is MCS 012-certified, V6.0 changes nothing for that job.
The changes apply where no MCS 012-certified product is available for a specific install — edge cases, complex roofs, non-standard configurations.
From 18 June 2026, all MCS certificate submissions must comply with V6.0. The date applies to when the certificate is submitted, not when the installation was physically started.
There is no published grace period beyond the three months between publication and the mandatory date. A certificate submitted under V5.0 after 18 June is non-compliant with the installer's scheme conditions. This could result in audit findings, potential suspension of MCS certification, or a certificate that can be challenged or invalidated — with knock-on consequences for the customer's SEG eligibility.
The standard is free to download from the MCS Standards and Tools Library at mcscertified.com/standards-tools-library.
Two parallel versions are listed. V6.0 applies to the Current Scheme. Installers transitioning to the Redeveloped Installer Scheme should use MIS 3002:2025 V2.0 (separate document in the same library). Most installers currently operate under the Current Scheme.