If you have received a COP9 letter from HMRC, it’s essential to take immediate and expert action. My Tax Accountant, as your COP9 Accountant London, is here to provide you with specialist advice and representation to navigate the complexities of the COP9 investigation. A COP9 (Code of Practice 9) investigation is one of the most serious forms of tax investigation undertaken by HMRC. It is issued when HMRC suspects serious tax fraud or deliberate non-compliance