InterfaxUS provides fax software to fax from your PC. InterfaxUS is the US software division of InterFAX. InterFAX has been offering computer-based faxing services since 1996. Initially a fax-on-demand service, the company went on to offer fax broadcasting, and in 1999 launched an Internet faxing system with send and receive capability. InterFAX serves tens of thousands of users, who send and receive over 60 million pages a year.