As of the 6th of January 2021, Wednesday, following the FCA's policy statement “PS20/10: Prohibiting the sale to retail clients of investment products that reference crypto assets”, Bitcoin ETP (BTCE) will be placed in close-only mode.
This means that you will not be able to open new positions with the instrument, but you can close any existing ones at any time you like.
All applications of COBS 22.6 "Prohibiting the sale to retail clients of investment products that reference crypto assets" can be found here. You can also find more information regarding the official policy statement publication here.
*The above-mentioned changes will apply to ISA & Invest accounts only.