Whenever you need to process changes to Non Refundable reservation, you would need to decide first whether cancellation fees will apply or not.
In case you would like to process changes without any fees you will need to leave tick box “Charge Cancellation Fee” un-ticked and if booking has been already fully paid, you will need to process refund depending on number of night you have shortened the stay.
In case you want apply cancellation fees to the guest stay, leave the “Charge Cancellation Fee” box ticked.