I recently sold my house in the UK , it sold within 24 hours and I was on the plane to Bangkok 6 weeks later. That’s best case scenario though in all honesty.
It’s only a requirement for people who will travel to a country that requires a covid test as an entry requirement so unless the uk changes their entry requirements then it won’t be an entry requirement in Thailand.
A 90day o issued in the UK gives you 90 days from the date of issue to enter Thailand and then the visa is valid for 90 days from the date you enter. I would assume that it would be the same for visas issued in Australia. If you want to be a hundred percent sure go to the forum on asean now website, there are some very knowledgeable people on there.
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