Exchange of information expanded: obligations to obtain and share tax-relevant information supersede bank secrecy and support cross-border tax administration. The Protocol replaces Article 25 with an expanded Exchange of Information framework: competent authorities must exchange foreseeably relevant tax information for application and enforcement of the Agreement and domestic tax laws, with confidentiality safeguards and restricted disclosure to tax and oversight authorities; use for other purposes requires mutual legal permissibility and supplying-authority authorisation. States need not adopt measures contrary to domestic law, supply unobtainable information, or disclose trade secrets or information contrary to public policy, but must obtain requested information even absent domestic interest, and bank or fiduciary-held information is not per se exempt.