You are a deemed resident if you were in Canada for 183 days or more. In this case, because you were gone for the majority of the year, you are not a deemed resident of Canada.
That said, you may still be considered factually a resident of Canada. This means based on the "facts" you were still resident, and considerations must be given to the following:
- Were you intending to emigrate when you left in January? Or were you always planning on visiting the other country, and Canada remained your home base?
- Did you still have ties in Canada? (i.e. Still had property in Canada, financial ties like bank accounts, trading accounts, etc.)
If you consider yourself "factually resident", then do not put a "change in residency".
Regarding your Australian tax returns, unfortunately our expertise do not extend to the Australian tax jurisdiction. The situation as you described, in the Canadian jurisdiction, would require you to file two returns for each of the tax year.
