A Flexible Forward (or Time Option) is like an FX Forward but it gives you more flexibility on the timing of the exchange.
If you know you will need or receive an amount of currency in a future window of time, for example a 3-month period, then you can fix an exchange rate for that period. You can execute your transaction at any date in that period at the rate you have accepted in advance.
Alternatively, you may need access to an amount of currency over a window of time. A Time Option will allow you to draw down from the total amount in smaller amounts throughout the window at the pre-agreed rate.
Note: The total amount of the Time Option will need to be exchanged before the end of the window otherwise the remaining balance will be exchanged on the final day of the window. If the actual exchange rate is more favourable to you on the settlement date, then you will still be obliged to transact at the rate agreed in the contract. Cancelling the contract can incur break costs which may be substantial.