Apologies if this has been discussed before - I couldn't find an answer when I searched.
I'm reviewing the tax return for an individual who became deemed dom on 6 April 2017. He has multiple bank accounts (as a result of previous income segregation exercises) and has invested funds with a handful of different banks, some of whom have further split investments between different porfolios.
Some of the banks provide UK CGT reporting. Some don't and we're calculating the gains manually. I've noticed that he occassionally holds the same funds in different portfolios. My concern is that all the units must be pooled for tax purposes. So if Bank 1 sells some units, the deductible costs will be a percentage of his entire holding across all the holdings. Bank 1 will only know the informnation on the units it has purchased so its CGT calculations will not be correct, as will all future CGT calculations by Bank 1 and all the other banks.
So my questions are: (1) do others agree that the units must be treated as a single s104 pool, despite being in separate banks/porfolios/nominees etc?; (2) if so, how do people deal with this in practice? Is it a case of keeping CGT calculations across the combined porfolios and calculating manually, or do practitioners rely on the CGT reports provided on the basis that it will/should all "come out in the wash" eventually?; (3) has anyone had any experience of HMRC's view/practice on this?
Many thanks for any thoughts.