If you are looking for an easy to use solution including CRM, customer care, and billing; you should definitely try out CitrusDB. CitrusDB is a Web based customer care and billing solution that uses PHP and a database backend to keep track of customer information, operational CRM, services, products, billing invoices and credit cards, and support information. I find it very suitable for small and medium companies.
CitrusDB
CitrusDB require PHP 5.0.4 or greater with register_globals turned off in your php.ini, any database supported by ADOdb (MySQL, Oracle, MsSQL, ODBC…). I did not tested security of the application, but there are some recommendation in the website to keep your server secure : in a private LAN with firewall, SSL protected web server with access limited to trusted IP addresses, or A Virtual Private Network or Intranet.


Below features of CitrusDB :

  • Customer Service
    • Track modifications to service records
    • Security and password access to database on a per user level
    • Stores general info, mailing address, billing address, and billing info about each customer
    • Import new customers from online order data
  • Service Management
    • Assign unlimited services or products to a customer record
    • Add custom fields for services/product information
    • Search by specified fields
    • Easy to add and modify services
  • Billing System
    • Custom billing cycles for each product
    • Printed invoices
    • Email invoices
    • Prepayment reminders
    • Credit Card Batches (import/export)
  • Support Tickets
    • Invividual database user notification
    • Group notification
    • Online requests integrated with account records
  • Customization
    • Modular functions to allow new pieces to work along side base functions
    • Works in multiple languages

For more information and download CitrusDB website. A manual that cover the 1.3 release of CitrusDB and written by Paul Yasi, is available here http://www.lulu.com/content/6837221.