iCDBILL is a free, simple, and secure on-line billing script. iCDBILL allows administrators to create an invoice for a client. Once the invoice is generated the invoice can be sent to the client, or viewed by the client in his or her control panel.

Features:
- allows for unlimited line items.
- extremely small (less than 100K).
- PHP code is commented on each and every line for easy changes.
- accept unlimited payment types or amounts - even split payments.
- clients and login and reprint invoices, view serial numbers, warranty information, and even pay invoices with a credit card.
- easy integration with online payment processors like WorldPay or PayPal.
- supports credit invoices for refund purposes.
- HTML invoice generation with downloadable and customizable invoice templates.
- support for all 4 browsers regardless of operating system.
- stores item name, sku, part number, serial number, and description.
- database is completely searchable.
- supports various tax values to suit your countries tax system.
- reports total amount of invoices paid, pending, and partial payments.
- shows you a year end or quarter end tax collected value for easy government remittance.
- optimized for 800x600 viewing to ensure all computer users can utilize the system.