Assuming invoicing is required, the following 3 results were found.
somewhat limited in terms of good customer service. It only really manages the payment side and the complicated tasks of invoicing, but Community Builder provides more options for your website members. If Joomlapolis ever complete the CB Subscription...
student record system and timetabling system (done via file upload). It included it's own timesheet / session management / invoicing system. The website was held on a virtual host running PHP and MySQL. There was no documentation, logs, notes, and any...
The Additional Learning Needs team at Bournemouth University use their website to reduce the paperwork and manage all the invoicing processes. The site is restricted to staff and students only.