Duke Energy is warning its customers to be wary of scammers who misrepresent the company and prey on utility customers.

Wednesday is Utility Scam Awareness Day and electric and natural gas companies across the country are warning customers about scams. According to one survey, the number of attempted phone scams have more than doubled in the past year.

Duke officials report that the most common scams targeted at utility customers include scammers demanding that you pay a large bill immediately, or face cut-off of your power. Scammers will frequently tell you that you have to buy prepaid debit cards and give that information over the phone in order to settle the fake debt, usually within a matter of hours. They could also request that you wire money.

And you should be cautious even if you have caller ID because scammers can now fake the information, so a call appears to be coming from a legitimate utility company.

Duke says to hang up immediately if you suspect a scam, don’t pay your utility bill with pre-paid debit cards or money wires, and don’t make immediate payments over the phone. Delinquent customers will always receive a regular notice in their bill, never a phone demand for immediate payment of your power will be shut off in an hour.