The Australian Taxation Office's Electronic Commerce Interface (ECI) Client software is an application that allows businesses with an Australian Business Number (ABN) to communicate with the ATO electronically. Some examples of the functions you can perform are: collecting documents/files from the ATO electronically;sending documents/files to the ATO electronically; checking your documents/files for errors before sending; send secure messages to the ATO via the Internet (Superannuation only).
To use the ECI application you need an AUSkey or ATO digital certificate. The latest version of the ECI Client software which supports Mac OS X is now available for download from this website. You should check that your Mac meets the minimum system requirements. The ECI Client software may not perform satisfactorily if your Mac does not meet these specifications.