Technically, yes. Under Thai immigration law in 2026, travelers entering on a Tourist Visa or a Visa Exemption may be asked to provide proof of "sufficient funds" for the duration of their stay. The official requirement is 20,000 Thai Baht per person (or 40,000 Baht per family). This can be held in any major currency (such as $600 USD or €550) and is typically expected to be shown in cash. While it is rare for immigration officers to check every traveler—they usually target those who appear to be "border running" or staying long-term on tourist permits—failure to produce the funds if asked can lead to a denial of entry. It is important to note that a credit card statement or an ATM balance on a phone screen is often not accepted; the law specifically calls for "ready cash" to prove you won't become a burden on the state. To ensure a smooth entry in 2026, it is highly recommended to have the equivalent of 20,000 Baht in your wallet before you land at Suvarnabhumi or Don Mueang airport, just in case you are selected for a random check.