How can DTV visa holders obtain a TIN and open a bank account after 180 days?

The two things are unrelated each other. As for a bank account, you're not supposed to get one. People who had accounts from before normally can keep them, but for newcomers is near to impossible.

I have both TIN and bank account on DTV. Getting the TIN was simply a matter of:

- Me being able to tell them the law (front desk aren’t tax experts on foreigners)

- Showing them the assessable income that requires tax filing.

- showing i stay more than 180 days.

Took 15 minutes to get the Tin in the morning at my local Bangkok office.

Bank accounts is a whole different matter and depends allot on your financial situation. TIN isnt a guarantee but helps. Its difficult, but not impossible. I opened my accounts without agent, but with very specific paperwork at a specific branch. Was frozen once, but quickly unfrozen with fresh KYC

But you don’t need a bank account to get TIN. Just need to show your spent assessable remitted money in Thailand (wise, revolut, credit card, atm withdrawals etc)

Interesting. I got my TIN while staying in Thailand on visa-exemption scheme and even paid taxes on all the money I brought and used in Thailand throughout the previous year. And I've never had a bank account in Thailand

Yes I have a bank account and have gone to my local revenue department for my Thai tax ID but didn’t bring my Thai bank statement. I’ll go again this week

yep cannot open a bank account on a DTV tourist visa.

As a tourist you cannot open a bank account. The tax office are not interested in tourists, even if you have been here more than 180 days

You already have your answers. Just because you become a tax resident does not mean you must file taxes. No bank account on a tourist visa, which the dtv is