Exchange of information powers enable cross border tax information sharing while preserving confidentiality and limited exceptions. Competent authorities must exchange information foreseeably relevant to implementing the Agreement or administering and enforcing covered taxes; such information must be treated as secret and used only by persons or authorities concerned with assessment, collection, enforcement, prosecution, appeals or oversight, with disclosure in public court proceedings permitted and other uses allowed only if both States' laws permit and the supplying State authorises. No State is obliged to adopt measures contrary to its laws or to supply unobtainable information or trade or professional secrets, but requested States must use their information gathering measures and possess powers to enforce disclosure even when information is held by banks, financial institutions, nominees or fiduciaries.