Thailand would have to increase tax revenue to pay for a NIT. Maybe just tax farang on their remittances and global income!
By 2023 almost 11 million Thais filed income taxes...but this was only about 25% of the workforce.
"The main aim of the Revenue is to close tax loopholes which formerly allowed Thais and some wealthy foreigners to reap huge profits from overseas investments, currency speculations and cash buildups in offshore accounts often held for years. Separately, the Revenue has published new reporting rules for digital platform operators to allow it to collect information on sellers’ total income from their online activities, aiming to nudge more online product and service providers into the tax system.
Many experts believe that the recent words of Lavaron Sangsnit are highly relevant to all recent tax announcements: “The world is getting smaller, more connected and traceable because of digitalization. In the past, it may have been impossible to detect tax evasion, but now it can easily be detected.” Now that Thailand has joined the Common Reporting System (CRS) of around participating 120 countries, financial institutions round the world will inform member governments of individuals’ transactions to fight tax evasion and protect the integrity of tax systems. In other words, when you send money abroad it is no longer a private affair."
Source. https://www.pattayamail.com/latestnews/news/thai-revenue-releases-personal-income-tax-data-449478