Check whether communications you receive from the ATO are genuine or spam
In an attempt to commit fraud scammers continue to pretend to represent the ATO in emails that request personal information and credit card details. The ATO has created a reference page on their website regarding these sorts of scams, and has also listed examples of these sorts of scam emails. The ATO will generally communicate with us on your behalf therefore if you receive an email directly from what looks to be the ATO, check the email against examples of scam emails per the below weblink, or check with us first.

http://ato.gov.au/General/Online-services/In-detail/Online/Online-security/
http://ato.gov.au/Examples_of_tax_related_scams