Short answer: To purchase a condo in your own name under the foreign ownership quota, the money must be transferred into Thailand from an overseas bank account, and it must arrive in foreign currency.
Can I use income that I’ve legally earned in Thailand to buy a condo in my name as a foreigner?
Even if you’ve lived and worked in Thailand for many years — and earned every baht through legal employment or business activity — Thai law does not allow foreigners to purchase a condominium using Thai-earned baht. To purchase a condo in your own name under the foreign ownership quota, the money must be transferred into Thailand from an overseas bank account, and it must arrive in foreign currency.
This requirement exists under the Thai Condominium Act, and the transaction must be supported by a Tor Tor 3 form issued by a Thai bank. The logic is based on foreign investment policy, but unfortunately, it excludes even long-term residents who have contributed significantly to the country through employment, tax, and community involvement.