Baht has been the national currency of the Kingdom of Thailand since 1897. Its sign is ฿ and its currency code is THB. Bhat is a decimal currency with a sub-unit “satang”. One Bhat is equal to 100 “satang” and 25 satang make up a "salung".
Currently circulating banknotes are of the series 15 and 16. These are in the denominations of ฿20, ฿50, ฿100, ฿500, and ฿1,000. The banknotes are designed with an objective to draw attention to the contributions of the Chakri Dynasty Kings towards the development of the country.
Each denomination note has a different dominant color. The ฿20 banknote’s color is green. The ฿50 banknote is predominantly blue. ฿100 baht banknotes are red. Banknotes of ฿500 denomination are purple and ฿1,000 banknotes are in brown-gray colored pattern. Size of the banknotes increases with their face value. The ฿20 note is the smallest and ฿1,000 is the largest in size.
The banknotes have a portrait of King Rama IX (Bhumibol Adulyadej) in the front. The King Rama IX lived from December 5, 1927 to October 13, 2016. At the time of his death, he was the world's longest-serving head of state. In the 15th series banknotes, the portrait is in the uniform of the Supreme Commander. However, in the 16th series, the portrait is in the Royal House of Chakri gown. The reverse side of the banknotes depicts images of other kings of the Chakri Dynasty.
Thai coins in public circulation are of six denominations viz. 25-satang, 50-satang, ฿1, ฿2, ฿5, and ฿10. Similar to the banknotes, Thai coins with less values are smaller in size compared to the more valued ones. All coins, like banknotes, bear a portrait of King Rama IX (Bhumibol Adulyadej) on the front. The reverse sides of the coins feature different temples in Thailand.
Prior to the adoption of banknotes and flat coins, Thailand used Cowrie Shells (shell of a marine gastropod), Prakab (Baked Clay Coins), and Pot Duang (Bullet coins) as their money.
King Mongkut (Rama IV) established diplomatic ties with many countries and implemented free trade. During his reign, an enormous increase in trade led to increased demand for the currency. The Pot Duang coins, which were prevalent at that time, were hand-made and fell short to meet the high demand. There was also wide-spread counterfeiting of the Pot Duangs. Therefore, in 1853, the King Mongkut (Rama IV) introduced the paper money, called Mai. However, the public preferred to use Pot Duang and as a result, the Mai, failed to meet the king's objectives.
During King Chulalongkorn’s (Rama V) reign in 1873, prices of copper and tin rose in the international markets. This led speculators to melt the coins and ship the metal overseas. As a result, there was an inadequate supply of less valued copper coins in the Thai economy. To address this shortage, the king decreed to issue a low-value paper money called Att Kradat (Low-value Paper Money). The Att Kradat was withdrawn in 1875, when new copper coins, from England, were put in circulation. In 1890, the governments prepared to issue a paper money called Ngoen Kradat Luang (Treasury Notes), however, due to the inefficiency in banknote management, these notes were never issued.