Over time the local currency equivalent of foreign currency amounts will fluctuate according to exchange rate movements. Usually at month end, there is a requirement to restate these amounts using the prevailing month end exchange rates.
SAP can revalue foreign currency GL account balances as well as outstanding customer and vendor open item balances.
In SAP configuration, you define the balance sheet adjustment account and which accounts the realized gain/loss should be booked.
A batch input session is created to automatically post the required adjustments.