Exchange of information obligations ensure cross-border tax cooperation while preserving confidentiality and limited by domestic law. Article 25 requires competent authorities to exchange information foreseeably relevant for applying the Agreement or domestic tax laws, including documents, and obliges the requested State to use its information gathering measures even if it has no domestic interest. Information must be treated with confidentiality equivalent to domestic secrecy rules and may be disclosed only to officials concerned with taxation purposes; core limitations permit refusal only where disclosure would contravene domestic law, be unobtainable, or reveal trade secrets or information contrary to public policy, but not solely because the information is held by financial intermediaries or relates to ownership interests.