I have been to Thailand 15 times over 15 years, 13 times on tourist visas and 2 times on retirement visas. Although I have had a return ticket to Australia for all times I have never been asked to see my exit air ticket return ticket to Australia or where my accommodation is...never
Australian residents in Australia long-term would be granted portability when they apply. Many people live only on their super in Aus and when they get below the threshold of $900,000 top-ups or $545,000 for a full top-up and apply for the AAP. Some are in their 70s or even 80s.
That is when Centrelink might be able to use their discretion, but perhaps not. Each case is considered personally. You must be in Aus anyway to apply for the AAP like 66.75 years to have it granted and do 2 years of residency in Aus before or after to be granted portability.
It is unlikely that if you deposited Bt65,000 in a Thai bank account it would need to be 65,000 each month over 12 months before you claim to have the funds to get a retirement visa. I tried some years ago and immigration told me "Put money in a Thai bank account and when you have Bt 800,000 come back for your visa" I gave up. It was simpler to get an OA retirement in Australia at the Thai Embassy. There were no restrictions on what I do with the money in an Aus bank after granting the visa and it was good for 2 years of multi-entry. for the 1st year. I wonder is that option is still available.
Possibly 90% of cases from Australians going to live long term in Thailand have not and do not have any requirement to pay tax in Australia. So where does that leave tax in Thailand? $27,000 is well under the tax threshold for persons over 67 y/o and Super is not taxed by the ATO anyway (mostly).
Well this site is for answers to general questions, there may be many others interested. There are other countries where a reciprocal agreement is available. Centrelink does not publish answers to personal issues. many are different. Thailand does not have a reciprocal agreement with Australia i.e 32 countries do where the answer will be different. from Centrelink.
First, remember if you are Aussie under 67 y/o your tax-free threshold is about $19.000 per year if over 67 y/o it is close to $35,000 that's why the AAP on its own is never taxed, it is under the threshold. Super also is not taxed. That has been my position now for 17 years. my income is $4,000 a year AAP and $29,000 p/y in Aus$12,000 super has no tax what-so-ever all above board with the ATO.
Some countries have AAP agreements with Australia there are about 32 of them. Different horses for different courses. Like Italy, you can go there and get their full pension, and hospital treatment etc, etc, perhaps 100,000 returning retired Italians have done that. It is a reciprocal agreement any Aussie can go.. Perhaps you might prefer Greece, Canada, or Japan there are many choices. Thailand is not one of those options.
No, if you lived long term in Aus at 67 y/o you will have served the 2 years to make the AAP portable. You can do that before or after you qualify. Most people living long term in Australia can get portability at 67 y/o (I stand corrected)