The financial terms of the deal were not disclosed. PayPal is already using the technology from Card.io in PayPal Here, its mobile payment technology for small businesses and casual sellers in March.

The employees at Card.io will be joining the PayPal global product team in San Jose to help the payment processor "create new experiences to make it even easier for consumers and merchants to use the PayPal digital wallet," said Hill Ferguson, vice president of global product at PayPal, in on Tuesday.

The current Card.io technology will remain available to developers for use in their own applications, he added. Card.io also said on its website that its SDKs (software development kits), available for Android and iOS, will continue to be available to developers to use in their applications. The Card.io SDK is a drop-in library for iOS or Android, and is priced by number of scans.

PayPal and parent eBay have been making acquisitions in the area of mobile payments. Ebay that it had agreed to acquire Zong, a provider of payments through mobile carrier billing, for about US$240 million.

Card.io like the Zong team will benefit from the opportunity to work on projects that will accelerate innovation at a scale that is not possible at a startup, Ferguson said.