The quiet evolution transforming jurisprudence on how to challenge a tax assessment

This article examines recent Federal Court decisions expounding the law for challenging a tax assessment issued under either s 166 or s 167 of the Income Tax Assessment Act 1936 (Cth) and the recovery of amounts assessed thereunder. It finds application of oft-cited principles bearing on what is required to show an assessment is excessive under Part IVC of the Taxation Administration Act 1953 and recovery of a tax debt unlawful heralds a welcome, if quiet, evolution in existing jurisprudence that better facilitates discharge of the statutory burden and increases confidence in the tax system. As will appear, certain preconceptions about the manner in which an assessment may be invalidated have been discarded and the notion of unreasonableness sustaining grant of equitable relief widened to include constructive bad faith.