In Australia, renters younger than 25 although over 21 years of age, are subject to a Young Driver Surcharge, which is a daily fee applied by the car rental companies. 


The amount depends on which car rental company you have rented your vehicle with. 


See the following guide:


SupplierYoung Driver Surcharge
Allows Probationary/ Provisional P Plate Licence holders
Budget
$16.50* per day, per under aged Driver
No
Avis
$27.50* per day, per under aged Driver
No
Enterprise
$20* per day, per under aged Driver
Yes
Europcar
$30.25* per day, per under aged Driver
No
Thrifty
$27.50* per day, per under aged Driver
No
Hertz
$16.50* per day, per under aged Driver
No
East Coast Car Rental
$9.90* per day, per under aged Driver
Yes

 

 * All extra add-ons will attract additional percentage taxes and surcharges.