A fledgling fintech startup is embracing time travel with a new feature that lets users switch the bank card they use for a transaction after they’ve already made the transaction.

Founded out of London in 2015, Curve offers a physical bank card and mobile app that aggregates all your existing bank cards into a single entity. Curve lets you manually add an unlimited number of bank cards to the app, which then syncs with the Curve card. So you may own a work credit card, personal credit card, and two personal debit cards, but all you ever need is your Curve card, which you can associate with any one of your actual bank cards using the Curve mobile app.

On the surface, Curve appears to be a clone of the myriad smart credit card devices that have previously gone to market, including Stratos and Coin, but Curve offers something different. It’s not a Bluetooth device that connects to your phone — it’s a bona fide bank card that slips in your wallet and can be used anywhere MasterCard is accepted. It works with chip-and-pin, magstripe, contactless terminals, and ATM machines.

Moving forward, Curve wants to make “Oops, I paid with the wrong card” a thing of the past, too.

Back in time

In what the company touts as a “patent-pending financial time travel capability” and “a world-first,” Curve users will be able to switch the card they used for a transaction up to two weeks after they’ve made a purchase. For example, if you intended to use a credit card to gain valuable reward points, but instead used your standard debit card, you can switch which card the transaction is made from afterward.

In terms of how this works under the hood, Curve literally just refunds the card you made the payment from accidentally, then takes the payment from another card — with one tap of the Curve app.

“This update is a solution to a common payments problem, and we know first-hand it’s a feature our users are excited about,” explained Curve product lead Arthur Leung. “Now, if a user makes a payment with the wrong debit or credit card, they can retrospectively switch the card they use to pay anytime in the next two weeks. No manually re-wiring money, no missed loyalty points, no unintentional incurred fees by using the wrong card.”

Above: Curve – Back in Time

Image Credit: Curve

Curve is currently available to business customers across Europe, and it claims that 50,000 beta signups have been responsible for around £50 million ($65 million) in payments in over 100 countries. A consumer version of the service is scheduled for launch this year. Though the near-term focus very much remains on Europe, a spokesperson told VentureBeat that longer-term the U.S. is on the company’s radar too.

But how rampant is the “wrong payment card” problem? Instinctively, it doesn’t seem like it would be that big a deal — sure, some people may wish they had used a different card on occasion, but is this so common that it deserves a feature such as the one proposed by Curve? According to the company, the feature was actually suggested by an existing customer, and following 30 hours of interviews with other users, the company found that “getting caught out with the wrong card” or “using the wrong card’ was a recurring pain point.

“We’ve already rolled out the feature to a test group of users, and it’s been hugely popular,” a spokesperson told VentureBeat. “Ultimately, the feature is one in a series of things we’re doing to make spending and saving effortless and free from outdated restrictions or complications.”

Curve has raised around $5 million in funding, including a $3 million seed round last September. We’re told that a larger Series A round of funding will be announced later this year.