This is the Invoice-SaaS system download gpl where multiple companies can do registration and each company will have their separate user panel.
Super Admin who owns the system will create the different subscription plans for users who are going to register to the system and also he can manage lot’s of other things.
Now Let’s say some company/user looking for an invoice management system, can directly register to the system and subscribe to suitable plans, and pay for it. Registered companies/user will get their user panel where they can manage their invoices and see the related records.