What is the ruling on the described financial transactions, especially concerning receiving dollars, then deducting a commission and converting the remaining amount into British Pounds, and how are direct currency exchange operations conducted between cities or countries in the current era, and is there a specific time for قبض (receiving/taking possession)?

It is permissible to work as a currency exchange broker for a known commission, provided that the condition of immediate possession (spot transaction) is met, whether actual or constructive, such as receiving a check or a bank transfer. This work is considered an agency for a fee. It must be observed that different currencies are exchanged hand-to-hand, while currencies of the same type require both equality (in amount) and immediate possession. Deferred sales or lack of immediate possession at the time of the transaction are not permissible.