The UK Finance Act 2004 introduces a new regime to require "promoters" and, in some cases, users of certain tax-based "schemes" (or tax shelters, in US tax parlance) to disclose details of the arrangements to the Inland Revenue. The Inland Revenue's action was likely inspired by the current US tax disclosure provisions that requires registration of certain tax-based schemes and reporting by taxpayers of their involvement in certain "reportable" transactions. This article addresses the following key questions in relation to the new regime: - what schemes/arrangements must be disclosed? - who is required to make the relevant disclosures? - when does the obligation to disclose arise? - what information is required to be disclosed? - what are the penalties for non-disclosure? - how does this compare to the US tax shelter reporting initiative?