The requirement to correct offshore tax errors legislation introduced in Finance (No. 2) Act 2017 is designed to require taxpayers to correct undeclared past UK tax liabilities in respect of their offshore financial interests on or before 30 September 2018. 

This date coincides with the start date for the OECD's "common reporting standard" when more than 100 countries will commence the exchange of tax and financial information.

Failure to disclose the relevant information by this date will result in very significant penalties (the standard penalty being 200% of the tax liability, subject to reduction to a minimum of 100% of the tax liability depending on the seriousness of the failure to correct).

On 19 January, HMRC published updated taxpayer guidance in respect of the requirement to correct legislation which can be found here.

In particular, these rules could apply to non-domiciled taxpayers who have received carried interest from non-UK assets since July 2015, and, if in doubt, such taxpayers should seek advice on how the rules might affect them.