Hi - from what we know, you would pay income on income earned in Thailand.
For example, we have customers who open a bank account here and transfer money from their home country into that account in Thailand.
They would pay tax on the interest earned on that money in Thailand. But not the money (principal) itself.
As always, if the amount of money is significant, then it would be a good idea to talk to a local accountant. We can certainly get you in touch with one.
That being said, its always good to have options. If you are planning to come soon, we recommend you keep your Australian based accounts and transfer money to live on while you're in Thailand. Then as you get more “comfortable” being here, you can transfer more funds as needed.