Policies Vary by Company It's important to keep in mind the policies of each company, since not all are created equal: Alamo: There is a per day charge for all additional drivers.
Alamo used to allow spouses as an additional driver for no extra fee, but as of 5/12/14 they have removed this benefit.
Dollar/Thrifty: Both companies typically charge per day for all additional drivers (including spouses).
Hertz: There is a per day charge for all additional drivers, but if you are a member of Hertz #1 Club (free to join), the fee is waived for a spouse or domestic partner.
This goes for all companies, regardless of whether the additional driver is a spouse or someone unrelated to you.
(You still need to list the additional driver on the contract, though.) In addition to California, where all drivers are free, state law in Illinois, Missouri, Nevada, Oregon, and Wisconsin allow the spouse to be an automatic authorized driver without a fee.
Dollar and Thrifty, which are both owned by Hertz, seem to be the only major brands that don't offer a way around the additional driver fees (unless you are a AAA member and the additional driver is as well as per above).
One often-overlooked extra when renting a car is a fee for additional drivers on a car rental contract.
Whether you plan on sharing the driving, or you're just looking to have the flexibility for a spouse or fellow traveler to get behind the wheel if needed, adding another driver your rental contract can be quite convenient.
AARP: Members get a free additional driver at Avis and Budget when booked with the AARP discount code at participating locations.
Costco: Members get a free additional driver at Alamo, Avis, Enterprise, and Budget when booked with the Costco discount code at locations in the U. K., France, Germany, Ireland, Netherlands and Spain.