If you're planning to order your key from overseas make sure that their part number is the same as the Australian version. I know for Lexus keyless remotes, there are numerous different frequencies: Japan, Taiwan, China, Korea, Singapore, Australia, Russia, etc. all have difference frequencies and can't be used interchangeably. Some models have the same frequencies as the US though and the keys can be imported from there but you have to be absolutely certain that the part numbers match. I suspect it would be the same for Toyota too. New Zealand also has the same frequency as Australia too if I can remember correctly.