GIFTS OF PROPERTY BETWEEN UNMARRIED CO-HABITING PARTNERS

Mr x & Miss Y are engaged and will soon to be Married Mr X has uk banking arrangements and is trusted wholeheartedly by Miss Y. Miss Y is inheriting readily marketable assets from the USA Nigeria and japan & Thailand(such as cash/bank balances and jewellery) and wants Mr X to manage them for an income. The jewellery is likely to be sold for £700,000 through auction    There is total trust betweem Mr x & Miss Y. 

The assets will have been held for only a matter of days before being re-invested.

Should Miss y sign a declaration of trust in favour of Mr X?

so they become joint owners?

The assets are being transferred from a USA inheritance.

At which point would capital gains tax be payable and a chargeable transfer of a gift arise?

A)t the point the declaration of trust is signed?

B)At the point the assets arrive in the UK?

C)at the point they are gifted by Miss Y?