Is it Debit or Credit?
When you use a debit card, you can sometimes choose how the purchase is processed. It can either be an online transaction or an offline transaction. If you punch in your personal identification number (PIN), its an online transaction it gets completed electronically and its done pretty quickly. If you dont use your PIN and you sign a charge slip instead, its an offline transaction. Offline transactions are processed much like plain-vanilla credit card purchases.
Even though you use a debit card, offline transactions are very much like credit card transactions. Your debit card might have a Visa logo on it, for example, so it runs through the Visa network. Its not a credit transaction, but it uses the same infrastructure.
In summary, when youre using a debit card:
- Choosing Credit makes it an offline transaction
- Choosing Debit makes it an online transaction
Who Cares?
So far, you may be unimpressed. Who cares how each transaction is processed? You might not, but banks and retailers do. When you do an offline transaction and simply sign a charge slip, the retailer has to pay a small percentage of your total purchase perhaps 2%. This fee goes to the bank that issued your debit (or credit) card as an interchange fee.
What about online transactions? Retailers can get those done for a lot less. They might only pay 10 cents or so per transaction.
As you might imagine, 2% of every purchase adds up to a lot of money. The banks and credit card companies would love for you to choose credit because they get 2% of every dollar you spend. Retailers, on the other hand, beg to differ. Theyd prefer that you choose debit so that they dont have to pay a hefty interchange fee.
In order to maximize revenue, banks give you an incentive to choose credit (or a penalty for choosing debit, depending on how you look at it). They may charge you a fee for online transactions usually in the ballpark of one to two dollars. Once you discover these fees, youre more likely to choose credit next time. In addition, they may offer rewards (such as airline miles or entry into a sweepstakes) each time you choose credit.
Of course, somebody has to pay the 2% interchange fee. Retailers dont pass it on to you as a transaction cost. However, it has to come from somewhere they have to build it into the price of the products and services you buy.

