When you use a Visa check card as a credit card with a signature, an additional amount of money is temporarily removed from the available balance in your checking account.
The merchant, not the bank, authorizes an additional amount of money to cover a purchase.
Types of Purchases
Any merchant can process an authorization, but the most common authorizations come from merchants in which you can end up spending extra money.
PIN-based transactions withdraw the actual amount of the purchase from your checking account. Some merchants that process an authorization will not allow you to use your PIN. Instead, they will “take an imprint” of your card and process it as a credit transaction.
There is no way to know how much money the merchant will remove from your available checking account balance. The best way to deal with that situation is to view your checking account after the transaction has taken place and to keep your receipt.
Because you might not know how much money has been removed, any purchases or checks that have not cleared your account could “bounce." Find out how much money has been taken out, and make sure you have money in the account to cover outstanding checks and other purchases.