Rodriguez said one of the biggest red flags should be any time a bill collector demands that you put money on a GreenDot or other prepaid card. Legitimate companies aren't doing that, he said.
In some cases, the maximum amount you can put on a prepaid card is $500. So a consumer or business could be asked to buy several prepaid debit cards to pay the back-due bills.
In some cases, clerks at stores like Rite Aid have warned consumers too by asking why they're putting so much money on Green Dot MoneyPak cards or iTunes cards.
Alarm bells should ring any time, too, when the caller on the other line says says a crew is on the way to shut off service unless you pay up. DTE isn't going to do that.
DTE said about 200 people were scammed last year by fake bill collectors pretending to be from the utility, and customers lost a total of about $120,000.
Why are the con artists going after small business owners?
Lynch at DTE said some information for a business easily can be found online. A little bit more information can be picked up with an initial phone call to make the fake collectors sound even more legitimate.
In some cases, they might have an actual amount owed by the business.
"It depends on how much information they've been able to acquire before they make the call," Lynch said.
What consumers need to realize, of course, is that scammers are upping their game to sound more convincing.