The transparency of the cover pool securing the covered bond is an essential part of that type of financial instrument, as it enhances comparability and allows investors to perform the necessary risk evaluation. Union law includes rules on the drawing up, approval and distribution of the prospectus to be published when securities are offered to the public or admitted for trading on a regulated market situated or operating within a Member State. Several initiatives regarding the information to be disclosed to covered bond investors supplementary to such Union law have been developed over time by national legislators and market participants. It is, however, necessary to specify in Union law the minimum common level of information to which investors should have access prior to or at the time of purchase of covered bonds. Member States should be allowed to supplement those minimum requirements with additional provisions.