Directive 2002/87/EC establishes a regime for supplementary supervision of credit institutions, insurance undertakings and investment firms within financial conglomerates. It prescribes definitions and quantitative thresholds to identify conglomerates, requires a single coordinator among competent authorities, and mandates close cooperation, exchange of information and access to records. The Directive addresses intra‑group transactions, risk concentration and governance, imposing minimum internal control and management standards for mixed financial holding companies and group structures.

Annex I sets capital‑adequacy methodologies (accounting consolidation, deduction and aggregation, book‑value/requirement deduction, and combinations), with the coordinator empowered to select the appropriate method. The text provides for third‑country equivalence checks, amendments to sectoral directives to prevent arbitrage, and transposition by Member States by 11 August 2004, with application to financial years beginning 1 January 2005.