The hold on a credit card that is used for a car rental deposit, can vary by company and may be specific to which location in particular you're using.
The most important thing to remember is that whatever amount is held, those funds will be frozen and unavailable to you for the full amount of the rental and then for the amount of time that it takes to get those funds reversed back into your account.
I contacted some major auto rental companies about their credit card holds for car rental deposit with mixed results.
(All links open in new windows)Budget.com
they process a credit card hold of total estimated charges plus 25% or $200, whichever is greater.
So, they have a $200 minimum hold (this minimum hold would only occur if your rental total was $199 or less). In order to calculate the amount held on your credit card if your total rental cost is over $200 just mulitply the amount of the rental costs by 1.25 which will give you the amount of the car rental deposit required.Dollar.com
They place an authorization (or hold) on the renter's credit card of the total estimated rental charges and any additional charges that may be incurred.
Funds held on your credit card will not be available for your use. Because the requirements vary by location, renters must look at the Local Policies guide for specific information on credit qualifications and requirements where you intend to rent.FoxRentaCar.com
They accept only major charge cards for deposit (no debit cards); they accept American Express, Diners Club, Discovery, JCB, MasterCard and Visa.
The credit card used must have enough for a minimum deposit of $200 or the total amount of the estimated charge for the rental plus $150 ($300 at their LIH Hawaii location) -- whichever is more.PaylessCar.com
The hold on a credit card for the car rental deposit will be the total amount of the rental estimate plus an extra $200. You can find local payment policies online when researching rates on their website.
other, not so specific responses I received, included:
states that the actual deposit amount can vary based on the approximated total cost of your rental. This cost is based on the size of the vehicle you are going to rent and how long you would like to have the vehicle.
If you need to know the exact amount of a deposit required for your rental, your best bet is to contact the specific location you want to rent from directly.
E-Z Rent A Car.com
States that the amount required for deposit can vary by location, but generally for renters who use a major credit card, a deposit for the total amount of the estimated rental PLUS an additional 35% will be applied. If accepted to use a debit card, the deposit will be the estimated total PLUS and additional $200
Gave no specifics as far as car rental deposit or the hold on a credit card.
All reps from these companies stated that the deposit amount can vary by your age, car type and location and suggested that you contact a location for the specific city or town that you would be interested in renting in, for more details.
All of the rental car companies did tell me though, that a cash deposit requires a much larger deposit than when you do the hold on a credit card.
*Note: Car rental companies can modify policy at any time; I make every attempt to maintain up-to-date info, but always check with an individual company to verify any policy. See: Disclaimer