According to Article 21(3) of the Transparency Directive (TD), the host Member State (MS) shall ensure disclosure of regulated information in accordance with Article 21(1) of the TD if the securities are only admitted to trading in the host MS. In this case the disclosure of the regulated information will be done under the legal regime of the host MS. Article 19(1) of the TD demands that an issuer who discloses regulated information files that information with the Competent Authority (CA) in its home MS. Since the home MS necessarily differs from the host MS (cf. to Art. 2(1)(i) and (j) of the TD) the CA of the host MS may not know that the issuer is required to disclose/has disclosed certain information and which particular information has to be disclosed/has been disclosed. How can the CA of the host MS ensure that the issuers fulfill their obligations in these cases?