Isnt running an exchange a service ?
The ATO classifies your company as a hobby if your turnover doesnt exceed $75,000 a year.
We still have over 30% company tax rates so yes we do pay tax on profits.
The GST just replaced sales tax. I also wonder if they will try and slap import duties and things like that on bitcoins not mined here.
The exchanges themselves would definitely be classed as businesses (the actual definitions are more complex than just turnover and refer substantially to "business like activities" - so your income can be low and still classed as business income or higher and still classed as hobby) and be taxable as such. As service providers, they'd also have a GST obligation upon reaching the threshold of $75,000 (technically they're collecting it from their customers and passing it on to the ATO as opposed to paying it themselves).
What's not clear at the moment is how the ATO will ultimately regard any income people using the exchanges make from their trading activities and what information the ATO might eventually (and I'd say this would be a fair way off - the ATO doesn't typically bring in policies which affect almost no-one) require the exchanges to disclose about their clients trading activity. The ATO already gets information from banks about interest earned on their customers accounts (it's pre-filed on your tax return if you use e-tax), and that's likely to be extended eventually to other forms of income which people often neglect to include on their returns. But in the short-term I don't think there are many exchange
users whose trading activities would be regarded as anything other than a hobby by the ATO (meaning that income wouldn't be taxable, but nor could they claim any losses).
