When a merchant or vendor initially makes a charge on your Visa credit card, a pending authorization is placed on your account. Once there, it may stay until they finalize the charge with their processor. If the merchant or vendor uses an outside processor to finalize this for them, the pending authorization will still stay 'pending' for a few days past when the charge posts. During this overlapping time period, it may look like there is a second charge on your account, but the authorization will disappear in time.