Will that be cash, charge or robo-money?

After years of being relegated to a seedy online market, Bitcoin is creeping into the mainstream — including a Midtown lounge that began accepting the digital currency as a method of payment recently and has since racked up $7,000 in electro-cash revenues.

“We like technology,” EVR co-owner Alex Likhtenstein told The Post. “I want my business to keep up with current technology.”

Unregulated and without any fixed value, Bitcoins are traded on the Internet for a constantly changing value, currently hovering around $120.

They work almost like money, except there are no banks to mediate the trade and the currency isn’t widely accepted.

Staff at EVR use tablets to pull up a service called BitPay, which functions like a credit-card processor. BitPay calculates a dollars-to-Bitcoins exchange rate and generates a unique code, which customers can scan to transfer money.

Fluctuations in Bitcoin value don’t worry Likhtenstein or his business partner, Charlie Shrem, who paid his initial investment in EVR in Bitcoins.

“The fluctuations don’t concern us because we’re not holding it, we’re just using it as currency,” Likhtenstein said. “I still get the same amount of money either way.”

On a recent evening at EVR, Gabe Sukenik, 24, paid his $45.73 bar tab with .3843 Bitcoins.

“Rather than handing your card over to a server and having to sign for it, a server can just come to you once and be done with it,” Sukenik said.

“I would use Bitcoins every day over dollars.”

Although Bitcoins are booming online, EVR is among New York’s first brick-and-mortar businesses to take them.

“It’s funny, because New York has one of the largest concentrations of Bitcoins, but there aren’t a lot of businesses that take them,” Shrem said.

Cansu Yerdelenli, co-owner of New Jersey-based A Class Limo, is also a member of the small Bitcoin club.

“I tell customers we take cash, credit and Bitcoins,” she said. “We wanted to get ahead of the game and . . . move from paper to digital currency.”

Most customers are happy to pay the old-fashioned way. Alex Knowland, 25, recently paid his tab at EVR in greenbacks.

“The US dollar is much more stable than Bitcoins. Bitcoins have gone from $200 for one Bitcoin down to $70,” he said. “I wouldn’t trust my purchasing power to something like that.”