The Financial Conduct Authority has invited ESG rating providers that expect to be in scope of UK regulation to join a voluntary pilot to help design the future regulatory reporting regime for ESG ratings. The exercise will test whether the proposed reporting metrics are clear, feasible, proportionate across different business models and useful for supervision, with the stated aim of avoiding unnecessary reporting burdens once the regime is live. The pilot is open to all potentially in-scope ESG rating providers, although a representative sample may be selected depending on demand. Data submitted through the pilot will not be used for authorisation assessments, and firms must still provide any relevant information through their formal authorisation applications. The FCA said the pilot is based on the proposals in Consultation Paper CP25/34 on ESG ratings regulation and does not indicate final policy. Interested firms must register by 13 May 2026. The FCA said feedback from the pilot could lead it to revise the proposed metrics, and it will consult on the regulatory reporting regime before final Handbook rules are set.