National Grid says someone claiming to be with the utility is calling Rhode Island businesses to demand payment for past-due bills.
The callers threaten to shut off service unless the customer agrees to wire money or provide their bank account information.
Attorney General Peter Kilmartin said last week that while the scam artists have so far only targeted businesses, he worries they could begin calling residential customers.
While National Grid does call customers to notify them about past-due balances, the utility does not demand immediate payment over the phone. Customers contacted regarding a late bill are given the option of paying by check, credit or debit card.
Also, the utility says it typically doesn't shut off services for past-due bills during the winter.