The UK Government has published Tax Administration and Maintenance: Autumn 2021, which includes consultations, calls for evidence, and other documents related to tax policy development and the administration, maintenance, and reform of the tax system. This includes a consultation on draft regulations for the introduction of new mandatory disclosure rules. The draft regulations provide for the introduction of the OECD's Model Mandatory Disclosure Rules for CRS Avoidance Arrangements and Opaque Offshore Structures. The model rules will require taxpayers and intermediaries to disclose information on these types of arrangements and structures to HMRC and will replace similar EU rules that were introduced previously for DAC6 and subsequently limited after the UK's withdrawal from the EU.

Another important document is the consultation outcome on transfer pricing documentation. According to the outcome overview, the government has decided that it will legislate to require the largest businesses to maintain a master file and local file, and a supporting summary audit trail, to take effect from April 2023. The requirements will generally cover businesses in CbC reporting groups. It is also noted that the government will not introduce an International Dealing Schedule but will keep this policy area under review. Note, UK HMRC has referenced the Master and Local file as the type of documentation to be retained to support arms-length pricing, but no formal requirements for the preparation or submission of a Master and Local file have been implemented.