Commerce / Invoicing Solution Whitepaper

We require a 5-6 page whitepaper/high-level-design that describes a potential architecture for the following requirements. Whitepaper should specify which base products would be recommended (e.g. cms, payment gateway etc) and highlighting where custom development effort would be required. Especially interested in evaluation of suitable payment gateway options that provide support for variable, recurring payments. ## Deliverables Project overview/requirements: - Our company is a reseller of usage based web-services - Users subscribe to service, creating account on portal - Subscribers agree to rolling monthly contract - Billed each month based on usage (variable size payment) - Payments will be in GBP (sterling) - Require commerce solution that can handle variable, recurring payments - When subscriber joins service, provides credit card info to payment gateway - No credit card information stored on our sites - Monthly charges are bulk provisioned one-time-per-month via csv file (1st of month) - csv file will contain: - customer id - invoice number - invoice period - payment amount - vat amount - total amount - file name (this will link to a pdf file which will be shown as link - contains full detail of bill) - Following upload of charge details, all subscribers sent mail indicating new bill available on-line (1st of month) - Charges applied to credit card (7th of month) - Payment gateway must provide callback of all paid/unpaid bills - Portal shall provide report of paid/unpaid bills - Subscriber can see previous 6 months bills on-line