SumUp provides a way for merchants to take debit and credit payments via their smartphone and today, the company has launched an API for its mobile point-of-sale solution.

The API is available for both iOS and Android and the company hopes that this will help businesses and developers bring payment processing functions to their own apps. The system works with credit and debit cards issued by MasterCard and Visa as well as registering cash payments.

It seems that it is payment-alternative week this week as iZettle launched in the UK, Payleven announced its Chip & Pin mobile solution at London’s App World conference, India’s Ezetap landed $3.5 million in Series A funding and MasterCard and ING started testing their mobile payment system in the Netherlands. It seems that we may be seeing more mobile attachments for card payments and even though Square is working on raising its profile via its deal with Starbucks will have more than a little to think about when it comes to competition.

SumUP CEO, Daniel Klein mobile feels that tech is changing the way merchants and their customers consider payments. He says:

“More merchants than ever before are using mobile technology to engage with their customers. Unfortunately, until now a lot of them have had to stop short of actually taking payments through their apps as they haven’t had access to the secure technology and know-how needed to do so. The release of our API means that this issue is solved.  They can now boost the potential of their apps by accepting payments seamlessly and securely, even on-the-go.”

The launch of the API follows SumUp’s completion of a $20 million series A round of funding so it is clear the money is being put to good use. Those who are interested in taking a closer look can find details about the API here.

SumUp was founded in 2011 and has expanded quickly. The company currently employs over 130 people and has offices in Berlin, London and Dublin.

TNW’s Managing Editor, Martin Bryant caught up with SumUp’s co-founder and COO, Petter Made at the Dublin Web Summit recently and you can find out his thoughts on the European mobile payments market in this video.