If some of your credit card details are entered incorrectly (e.g., ZIP code), Perusall may not be able to successfully charge your credit card. If you are unable to complete your purchase, check to make sure the following are correct:

• The 3- or 4-digit security code must match the number printed on the front or back of the card.
• The billing address must match what your bank or credit card company has on file for your billing address.

Unsuccessful charges sometimes will show as "pending" charges on your credit card or bank statement. These are temporary and do not indicate that your card has been charged; these pending charges will disappear on their own.