If your card has a major credit card logo, you can use it as a credit card anyway even though you don’t have a credit card account. Been there, done that hundreds of times. Your transaction will automatically be converted to a debit transaction. Just be sure you have the funds in your checking account to cover the charges. Actually debit cards cost the merchant less in transaction fees than credit card purchases. The The Dodd-Frank Act with the Durbin Amendment limited debit card transactions to about $0.25, credit card transactions remained mostly unchanged at about 2% of the value of the transaction. A $40 transaction with a PIN is about $0.25 while a credit card is about $0.80. Also, the amount of the transaction can reduce the credit card fee, but it will still be higher.