Now more than ever, people are opting to pay for gasoline at the pump. While convenient, there is a drawback debit card users should be aware of.

Retailers say they take a risk by offering pay at the pump service. They have no protection against people who use debit cards but do not have enough money in their bank accounts to cover the cost of the gas. That's why some companies put holds on debit cards purchases.

Deputy District Attorney Joe Kisner says gas stations usually put a hold of about $40 on a debit card purchase. He says it's up to banks to decide how long the hold will last. Some hold the money for up to three days.

This can be a problem for people with tight account balances. If a large portion of their money is blocked without their knowledge, they could easily let a check bounce.

Experts say you can avoid the problems these holds can cause by closely monitoring your bank statements. Also, pay inside instead of at the gas pump and ask the merchant and your bank about their hold policies.