When a credit card token is stored with the merchant account, there is a request to process a $1.00 authorization against the credit card in a separate transaction. This is not a sales charge against the card. It is an authorization that the PCI security council requires to prevent credit card fraud and verify that the merchant is an authorized processor.
A authorization for the charge will clear between 1 to 8 days depending on the credit card issuer, but will not charge the card for any money. This allows the client to know that a token was generated against their card and improves their card-holder security.