The scam generally targets businesses, police said.
A person calls the business claiming to be a PG&E employee, informing the victim that they must immediately make a payment for an overdue bill or the service will be shut off, according to police.
The businesses are asked for bank account, credit card or pre-paid debit card information to pay the bill.
Police said PG&E has also noted a similar scam conducted by email under the same pretense.
PG&E does not ask for personal or bank or credit card information over the phone, police said.
Anyone receiving suspicious calls or emails may contact PG&E customer service at (800) 743-5000 or police at (650) 738-7314.