Almost all gas stations require you to either prepay with cash or use a debit or credit card for gas. Most gas stations accept debit cards at the pump, so you can simply pull up to the pump, slide your card in and begin filling up your tank. Unless there is no card reader at the pump, you do not have to prepay while using a debit card.
Insert your debit card in and out of the marked credit and debit card slot. A picture of a card is typically next to the slot, indicating which way to slide your card in. A keypad and LCD screen are also next to the card slot.
Press "Yes" when the screen asks you if you wish to use your card as a debit card. Enter your PIN number and press "Enter." Then enter your ZIP code if the on-screen instructions request it.
Remove the gas nozzle, select your grade of gasoline and begin pumping the gas when the screen instructs you to do so.
Hang the nozzle back up when you're done, and press "Yes" on the keypad to receive a receipt or "No" if you do not wish to receive a printed receipt.
Most gas stations accept debit cards at the pump, but if the card reader is broken or your gas station does not accept cards at the pump, you'll have go inside and give the clerk your card and prepay for the gas. Tell the clerk how much you want to prepay and go outside and pump your gas. Come back in after you're done and swipe your card and enter your PIN. Tell the clerk before you swipe your card if you did not use all of the prepay amount, because the clerk will have to adjust the price.
Some banks issue $50 to $75 holds on your debit card when you use your card at gas stations. The hold can last up to three days.