Credit Cards 
What is a Credit Card Security Code?
For American Express Cards
For Visa, MasterCard, and Discover Cards?

Credit Cards

Avis accepts most major credit cards as credit identification at the time of rental.
Accepted Card List

American Express
AT&T Capital
Diner's Club International
Diner's Club (US issued with MasterCard logo)
GE Capital
Note: Some locations may not accept each of the referenced charge cards.

Most US locations also accept bank debit cards with the Visa or MasterCard logo as credit identification at the time of rental if you are at least 25 years of age. Canada locations do not accept bank debit cards as a form of credit identification.
What is a Credit Card Security Code?

Credit Card Security Code (CVC/CVV/CID) is a 3- or 4-digit number printed on your credit card. It provides added security when you use your card on the Internet. The number appears only on the card itself, not on receipts or statements.

We ask for the security code (CVC/CVV/CID) when you enter your payment information. This helps ensure that anyone using a credit card on has the card in his or her possession and is not using a stolen credit card number.
Each credit card company has a different name for the security code and puts it in a different place
For American Express Cards

The Security Code (CID) is always located above the account number on the face of the card, sometimes on the left side and sometimes on the right. Note: Some American Express cards have a 4-digit number below the account number. This is not the security code(CID)

For Visa, MasterCard, and Discover Cards?

Turn the card over and look at the signature box. You will find either the entire 16-digit credit card number or just the last 4 digits, followed by the 3-digit Security Code (CVC/CVV).