Recognising Thai currency quickly — denominations, colours, and the security features worth knowing.
20 THB (green), 50 THB (blue), 100 THB (red), 500 THB (purple), 1,000 THB (grey-brown) — colour-coded for quick recognition even before you can read the numerals.
1, 2, 5, and 10 THB coins in circulation; the 10 THB coin has a distinctive two-tone silver and gold appearance; 25 and 50 satang coins exist but are rarely used.
Every note and coin carries the King's portrait — treating currency disrespectfully (stepping on it, defacing it) is taken seriously; never place anything on top of currency at a table.
Higher denomination notes (500, 1000) have security threads and watermarks — genuine concern is low for tourists, but check large notes received in change at less formal settings.
