I am pretty sure that UK and Aussie expats have to pay income tax on any rental property they own in their respective countries, regardless of whether they are resident or non resident of their own countries. It's 20% tax in the UK, but you can deduct outgoings like mortgage interest and expenses. I also know that UK expats pay no tax though on their interest earned from savings in UK banks. Not sure about Australia, but I do know that the ATO charges capital gains tax (eg on the sale of an investment ptoprty in Oz) at a higher rate if you are an Aussie non-resident, I think the rate is 29% tax on the gain.