Receiving dollars into a pound account doesn't mean the dollars will be deposited as is.
Steps
The bank may convert the transfer to pounds at the applicable exchange rate, or there may be other requirements depending on the type of transfer and the account.
If holding dollars is important to you, open or use a qualifying dollar account before sending the transfer and ask the bank about receiving details and fees.
The figures, fees and limits in this answer vary by bank and change over time — confirm them with your bank or the official source before acting.