根据ACS的官网FAQ,
7. Can I contact the office regarding the progress of my application?
We advise against it, as this will result in a delay in processing your application.
You can track the progress of your application through our website at http://www.acs.org.au/skillsapp/index.asp, once you have been allocated a reference number and given a password which will be emailed to you within 10 working days of your application being received.
Thank you for your Skills Assessment Application to the Australian Computer Society. Your application reference number is xxxxxx.
Please be advised that your result letter is about to be posted to you by registered post and the tracking number is xxxxxx.
If you wish to track your registered letter please call Australia Post on 13 13 18 and quote your tracking number. Note that your tracking number may not be available immediately. Allow two working days before checking. Alternatively you can submit an online enquiry via the Australia Post website at online enquiry and enter your tracking number in the enquiry section.