Before renting a car in Canada, make sure that the principal driver and all additional drivers are all at least 21 years of age and that they have a minimum of 12 months of driving experience.
Drivers from 21 to 24 years of age are required to provide a higher deposit than drivers 25 years and over. This deposit, in the form of a "pre-authorization" on the credit card of the principal driver, corresponds to the amount of the deductible payable in the event of an accident ($500 to $1,000).
When you return the car at the end of your road trip, and after verification, this authorization amount is cancelled and all confidential information pertaining to the card is destroyed.
Note that a rental surcharge will also apply for drivers from 21 to 24 years of age (about $25 / day depending on the company). This amount is to cover the extra insurance coverage required for young drivers.
Drivers from 21 to 24 years of age can drive the following kinds of rental vehicles: sub-compact, compact and standard.
For insurance reasons, drivers from 21 to 24 years of age are not permitted to drive SUVs or minivans.