The current state of the market for European players in the payment space, is that it's not startup friendly.
Take companies HQ in Europe like Worldpay (London), Adyen (Netherlands), WireCard (Germany), Fidor Bank (Germany) and Mambu (Germany).
Not one company wanted to talk to my startup.
No problems with US based players. They are more than happy to work with startups and will actively work with you to become a unicorn.
After all, the higher transactions the startup does, the more money they earn.
I work at Mambu and our clients are predominantly Startups - https://www.mambu.com/clients Feel free to drop me an email at [email protected]
Although we do not provide payment services to businesses, rather a SaaS platform for Financial Institutions (e.g. WireCard may use Mambu as their Core Banking when providing banking services to their customers).