Thai national currency is Thai Baht. Stable and strong currency, supported by assets of Thailand – world’s largest rice exporter.
In Thai banks you would be able to exchange merely any foreign currency. Some Thai banks can impose restrictions on ATM cash withdrawals, some simply prohibit ATM withdrawals. You can pay bills in restaurants, shops etc. with your card, but sometimes there might be problem with ATM withdrawals.
There 2 options:
1. Always take some cash when you go out.
2. Visit bank with your passport and card, withdrawal cash directly from bank branch.
Thai people are very sensitive towards their king and all royal family. Don’t publicly smack, tear or paint banknotes. Because they have portrait of the king, so it can be regarded as an insult.