This document explains why there is a small charge in your Yahoo! Voice account.

These are authorizations,  not real charges. You will see a small amount charged then refunded from Yahoo! as a credit. This is done as a security measure to verify that the card is active, and that you have authorized use of it.

We vary the amount of the credit from user to user. We ask you to provide this exact amount in the verification window of your Yahoo! Voice account page so that we know you are you.

We've found that this account-check method is an effective way to protect you and our other customers from credit card fraud.