Are their pain points with integrating into an existing CRM and ERP. Would also like to understand gaps that are currently not addressed by any of the readily available options.
Stripe is suitable for online subscription management. Integrating the same with a web based ERP/CRM system should not be a big problem, provided the ERP vendors give provision to integrate.
BACS is another payment mechanism by which subscription billing can be automated. The enterprise application need not be web based but should be able to generate a list of all subscribers and their amounts due in a particular format in csv file.
Hope this helps.