Exchange of information requires competent authorities to share foreseeably relevant tax information, subject to confidentiality and limited exceptions. Article 26 requires competent authorities to exchange information foreseeably relevant to applying the Convention or administering and enforcing domestic tax laws, with received information treated as secret and disclosed only to persons or authorities concerned with assessment, collection, enforcement, prosecution, appeals, or oversight and used solely for those purposes unless both states permit other uses. Limits prevent obligation to act contrary to domestic law, to produce unobtainable information, or to disclose trade secrets or information against public policy, but do not permit refusal solely for lack of domestic interest or because information is held by financial intermediaries.