Should I apply for a retirement visa to Thailand before arriving or in my home country?

google search: thailand post on 3 million insurance cover required for OA retirees

i'd say mandatoryhealth insurance required by OA visa not quite useful as pre existing health problem are all excluded, so better opt for O retire visa which does not require this, besides it is not possible to change OA to O while in thailand, insurance premium will be very costly too as one gets older

Im from NZ im going to apply for OA visa from here you get multiple entry plus you can get 2 years out of it if you do a border crossing.You can use your Aussie bank account.I wouldn't advise not having insurance like the O visa if something happens even catch covid it will cost you big time.After 2 years if you still enjoying Thailand you can swap to O visa.Only my opinion.

Do you intend visiting Australia every 18-24 months? If so the OA is by far the best option

Do you have money in Thai bank already?

Do it here I did. Easy but you need the funds in the bank for long enough to qualify, 3 months.

Yes do visa Thailand 🇹🇭

I would advise against getting a Non-oa in Sydney, the ongoing insurance requirements are much higher and carry on year to year

Easier in country, if you have the funds etc.

60 day visa to get here

(I was advised not to just arrive on a 30 day stamp, as it's harder to convert to non-o, you have less time to open a bank account, move money and submit the 90 day non-o)

Visit your Embassy, obtain an Embassy Certified Copy of your passport

Open Thai bank account.

Needing the above copy of passport, you address in Thailand (TM30 copy) and a Thai friend to help, vouch for you and your address details.

I recommend Bangkok Bank, head office Bangkok, they have English speaking staff who are familiar with the process.

Move 800k

Apply for no-no retirement 90 days 1900thb (nb you need a minimum of 15 days left on your entry stamp)

After money seasoned for 2 months, apply for 12 month extension, 2000thb

Come in on a 30 day and apply here. It’s easy peasy. 1,900.00 Bhat. Just Google the requirements for entering Thailand as it changes day to day.