Application service provider (ASP) featuring e-commerce software for use as a payment gateway that authorizes processing of credit cards or direct payments for merchants; Software as a service (SAAS) services featuring software for creating and issuing and managing invoices, tracking customer balances and customer relationships, create payment deadlines and provide periodic payment reminders, provide customer portals that enable customers to access stored records and make payments, create and deliver payment links to customers, accepting and processing one-time and recurring payments, create customized customer Internet landing webpages, and integrating and communicating with accounting software platforms and with third parties and with third party financial institutions