Income not withdrawn to bank

[superconfused]

Do I have to pay capital gains on money I have not withdrawn to my account?

If so I have a followup question:

The amount is in USD but my currency is GBP. How do I know what an authoritative USD to GBP conversion rate would be at the exact date and time when the money was received?
As it's a different currency i don't know how the amount should be in pounds and therefore how much tax to pay.

[pawncob]

Superconfused is an apt name. Can you post a meaningful question please? Full explanation required.

[superconfused]

Superconfused is an apt name. Can you post a meaningful question please? Full explanation required.

I think the question was quite clear, but I've solved this problem by downloading the list of currency exchange rates for the month.

[superconfused]

The lists are shown here in case anyone else is asking a similar question: https://www.gov.uk/government/publications/hmrc-exchange-rates-for-2021-monthly

[bd6759]

1. Yes

2. As you’ve discovered, the official exchange rate is a matter of public record.