New EU rules require intermediaries such as tax advisers accountants and lawyers that design and/or promote potentially aggressive tax planning schemes to report certain tax arrangements to their domestic tax authority. The EU rules set out two categories of ‘hallmarks’ to identify reportable arrangements: generic hallmarks such as those in which the intermediary is entitled to receive (for example a fee based on the amount of the tax advantage derived from the tax scheme); and specific hallmarks such as planning to use tax losses. Given the retroactive nature of the rules it is recommended that from Summer 2018 all UK intermediaries advising and assisting with implementation of cross-border arrangements consider and confirm whether the transaction is within the scope of the EU rules unless it is clear the advice is covered under legal professional privilege (LPP) in which case any...