The insurance excess is the amount charged to the renter in the event of accident liability or if no third party is identified during the rental.
The insurance excess is taken by card imprint when a card payment is made by the renter. This is not debited in advance.
It is used to cover any external damage. Any potential internal damage is covered by the security deposit (bond), which is to be given to the owner prior to departure.
The insurance excess applies to each and every incident/accident, meaning you could be liable to pay for multiple excesses.
The amount to be paid for the excess depends on the country in which the vehicle is registered along with in which country your licence was issued. Please refer to this page for more information.