All financial transactions must use currencies defined in this screen. The actual currency of a transaction is referred to as the Prime Currenc. A Base Currency is the principal reporting and book-keeping currency which has an exchange rate of 1.
The Base Currency also could be a Prime Currency of a transaction.
This setup is pre-loaded with some currencies from the Business Model which you have chosen at the initial sign up. You can add, remove or amend the currencies using this option.
