Hi,
Carried interest, for capital gains purposes is usually taxed on an arising basis.
This means that the gain is generally taxable in the year you receive it.
As you were resident in the UK when you received the carried interest, the full amount should be declared in your tax return.
There are some circumstances when you can elect for carried interest to be taxable on an accruals basis.
Further information and guidance on how to make an election can be found at:
IFM37710 - Accruals basis elections: introduction
Thankyou.