There is no upper limit on the amount of foreign currency (cash in other currencies, such as USD, EUR, GBP, etc.) that you can bring into Thailand as a traveler. You can enter with any amount.
However, you must declare it to Thai Customs if the total aggregate value of foreign currency cash (banknotes and coins) you are carrying exceeds the equivalent of USD 20,000 (or its equivalent in other foreign currencies, calculated at the current exchange rate).
• This rule applies to the combined total across all foreign currencies you have with you (e.g., USD + EUR + JPY added together).
• If your amount is USD 20,000 equivalent or less, no declaration is required for foreign currency.
• Declaration is done by filling out a Foreign Currency Declaration Form provided at the airport/port of entry (typically at the Red Channel/“Goods to Declare”).
• You need to present your passport, boarding pass, and the form to a Customs officer.
This is based on Thailand’s Exchange Control regulations (Ministerial Regulation No. 25 B.E. 2530) and is consistently referenced on official Thai Customs pages, Thai embassy sites, and related government-aligned sources.
A few notes and variations that sometimes appear:
• Some sources (including certain Bank of Thailand references or advisories) mention a stricter/practical threshold of around USD 15,000 equivalent (or about THB 450,000–500,000 total including any Thai baht cash) for combined cash/negotiable instruments to trigger declaration—often advised to declare proactively if near or above this to avoid issues, disputes, or delays.
• But the primary legal threshold for foreign currency alone remains USD 20,000 equivalent, as stated directly by Thai Customs and embassies.
• For Thai baht (THB) cash being brought in, there is generally no strict inbound limit mentioned in most sources (unlike outbound restrictions), but if combined with foreign cash it may factor into the ~THB 450,000–500,000 combined declaration guidance in some contexts.
Failure to declare when required can be treated as a criminal offense, potentially leading to fines, seizure, or other penalties.
For the most accurate and up-to-date advice (as rules can be subject to interpretation or minor updates), check the official Thai Customs website (customs.go.th, English section) or contact them directly before travel. At airports like Suvarnabhumi, look for the Red Channel if you need to declare.