SolidState Billing is a web-based Customer Management and Billing solution designed for web hosting providers, particularly hosting resellers. It is developed in PHP, uses MySQL as the backend database, and is licensed under the GPL.

Key features of SolidState Billing:
- Open source (GPL)
- Support for PHP4 and PHP5
- Use MySQL database
- Independent Payment Gateways Module
- Indepenent Domain Registrar Module
- Multi-user system
- The ability to integrate third-party modules
- Using Smarty templates
- Checking the active, inactive and pending accounts
- Attachments to the memos Account
- Sending predefined e-mail'ov for new customers
- Creating and editing accounts, which can be printed or sent by mail to its customers
- Accounts can be generated by one or all at once
- Payments
- Set one-time and monthly payments for each service / service
- Services have a duration of 1,3,6 and 12 months
- Domain registration through API Directi