Any fellow Crazy Domains customers might find the below article interesting. From the way I read it, the impact on customers will be if you have already lodged tax invoices prior to receiving amended tax invoices recently. The auDA (.au Domain Administration) believe that Crazy Domains have been in breach of their registrar agreement by distributing incorrect tax invoices.
My understanding is that Crazy Domains owning company (Dreamscape Networks) is not an Australian company and therefore does not fall under Australian GST rules. If a customer purchased a product from Crazy Domains between 3 December, 2012 and 5 July, 2013; your tax invoice is incorrect. Crazy Domains should have sent you an amended tax invoice. However, if you have already claimed GST related costs, you may have claimed the incorrect amount.
It's definitely worth reading the article if you are a Crazy Domains customer who purchased a product during that time. Read the article here - http://www.auda.org.au/news/crazydomains.
Til next time ...