Is the amount in the original currency or the account's currency?

When an end-user uses their card in a foreign currency, the bank will convert that to its local currency (e.g. GBP) using the daily rate, to show to the customer while the transaction remains pending.

When the transaction is settled and the funds are taken by the merchant, the initial foreign currency amount is again converted. Due to currency fluctuations, the initial and the settled amounts may differ.