Our API directory now includes 56 billing APIs. The newest is the Merchee API. The most popular, in terms of mashups, is the Stripe API. We list 5 Stripe mashups. Below you'll find some more stats from the directory, including the entire list of billing APIs.
Open Banking has launched two API specifications; Accounts and Transaction Information and Payments Initiation. These API specifications will allow banking customers and small business to share their financial data with third-party applications, and will be live from January next year.