Car rentals are subject to many conditions which vary from one country to another and from one company to another. Generally the vehicle must be returned in the same condition it was rented in, and often must not exceed mileage restrictions, otherwise, extra fees may be incurred.
For insurance reasons, some companies stipulate a minimum and/or maximum rental age. In some cases, the minimum age for rental can be as high as 25, even in countries where the minimum legal age to hold a driver’s license is much lower, e.g. 14,15,16 or 17 in the United States. It is not uncommon for there to be a young driver surcharge for all drivers aged under 25. On average, most car rental companies will only to rent to drivers who are at least 20 or 21 depending on the company. The companies Hertz, Dollar Car Rental, and Thrifty have a minimum age of 20. Alamo, Enterprise, Avis, and all other reputable companies have a minimum age of 21. Certain luxury vehicles may be restricted to those 25+. The US states of New York and Michigan are the only ones who mandate via state law that rental car companies cannot refuse service on the grounds of age if the customer is at least 18 years of age or older. In addition, some companies will rent to 18 and 19 year olds if they are military or government personnel.
In all cases, a valid driver’s license is required in order to rent a vehicle, and some countries require an International Driving Permit (IDP).
The majority of car rental companies require the use of a credit card to charge additional fees should a defect be found with the car on its return or for road tolls, motoring related fines, or missing fuel. In lieu of a credit card, some companies require a large cash deposit. Some companies permit a debit card for deposits, typically with proof of a round-trip travel ticket, e.g. an airline, bus, or train ticket.