It’s been a little over a month since the U.S. Mint produced its last penny. Businesses are starting to run out of them and trying to figure out what to do if they need to make change — especially because rounding up or down five cents can have a big impact on a business's bottom line.

The Federal Reserve distributes pennies to banks and credit unions. A spokesperson said it’s using available inventory to fulfill penny orders. 

That said, some of the Fed’s distribution sites are no longer doing penny transactions.

Steve Kenneally with the American Bankers Association said banks are telling him that they had penny inventory on hand, although it was “shrinking perilously low.”

Now he expects banks to start having difficult discussions with their customers, he said. Among banks’ customers? Retailers.

Cash makes up roughly 50% of transactions at convenience stores, said Jeff Lenard of the National Association of Convenience Stores. 

A lot of them are rounding in favor of the customer. Meaning?

“Rounding down to the nearest nickel in terms of the price and rounding up in the change that you give customers,” Lenard said.

He said a penny here, and penny there adds up — big time.

“In convenience stores alone, that costs the industry about a million dollars a day if every store were to do that,” Lenard said.

They can’t just switch to all digital payments, he said — those come with processing fees. And some customers just like paying in cash.

It’s a similar story in restaurants.

“To round in the customer's favor consistently could cost the industry between $13 and $14 million a month,” said Sean Kennedy with the National Restaurant Association.

Kennedy said without a national rounding standard, things can get confusing.

If you round up in a customer's favor, for someone who's paying in cash, but then make people paying with credit cards pay the exact amount, no rounding, “you could have nuisance lawsuits that come up,” Kennedy said.

The federal government could clear things up, said Danny Soques, an economics professor at the University of North Carolina Wilmington.

“Either some guidance from the Treasury, the executive branch, or directly from Congress through law,” he said.

He gave Canada as an example — which also stopped producing its penny. There, they round to the nearest five cents for cash transactions, but keep exact amounts for electronic payments.