What are the requirements to apply for a retirement visa in Thailand after arriving on a visa exemption?

Terminology is important so forgive me. You didn’t arrive on a VOA and got 30 days. You arrived visa exempt - there is a big difference.

To apply for a “retirement” Non O visa in country you’ll need to open a Thai bank account and deposit 800,000 baht in to it transferred from overseas.

You’ll need between 15-21 days left on a valid stamp to apply so if you don’t act swift and get the bank/transfer done you may need to get the 30 day extension to give you leeway.

Here’s the full requirements for the Phuket office. Another local office may differ in their requirements.

Didnt think VOA could be changed in country. The experts will know.