Our bank gives us a terrible rate to transfer between USD currency account and GBP current account. Is the difference an allowable business cost, such as a Bank Charge or Bank Fee? We're losing a sizeable amount of value each time, and would like to be able to write it off against profits if possible? As an absurd example - if I were to transfer $1000 USD and the bank gives me £10 GBP, when it should be more like £700, would the £690 count as a business cost? Thank you!