iZettle announced on their website that American Express coming on board as an investor. This makes it the second credit card company to participate in the Series B funding round along with Mastercard. We covered the bulk of their series B funding last June, which included investments from Greylock Partners, Northzone, SEB Private Equity, as well as their series A investors Index Ventures and Creandum.

In the past, American Express charged nearly 1% more per transaction than iZettle’s other supported credit card companies. But now in Finland, they charge a flat 2.75% for all supported cards.

Visa is noticeably not on their investor list, as Visa dropped compatibility with the Swedish payment solution last July, cutting out the large bulk of people in the Nordics that carry only a Visa Electron card issued by their bank. Visa is an investor in the similar American smartphone payment solution, Square.

But things may be progressing with Visa. Last month, iZettle sent out an email to customers saying, they are “in a positive dialogue with Visa Europe and are confident that we have made some good progress.”

iZettle has also recently announced Android compatibility with a new device that plugs into the headphone jack.