The coins of Cooch Behar mint were circulated in Bhutan until 1789. In the 18th century, Bhutan currency consisted of Bhutan rupee in silver which were used for trade purpose in the plains. This was followed by coins struck in alloyed silver, copper or brass which were used for local purchase. Bhutan coins are divided into the following periods: Period I, Period II, Period III, Period IV and Parliamentary Democracy.
Old Bhutanese coins were known as "Ma-trum" or "Chhe-trum" and were produced by several local chieftains. Quality of striking of Bhutan coins was improved in the 20th century under King Druk Gyalpo Ugyen Wangchuck. Fine machine struck silver and copper coins struck later, marked the beginning of Modern Coinage in Bhutan. However, the use of these coins remained limited since the system of barter was more predominant. Even government officials were paid in kind, rather than cash.
In the mid 1950s, Bhutan’s economy gradually monetized. Nickel coins struck with the die of silver coins was widened. In 1968 Bank of Bhutan was established and the barter system eventually faded. Monetary reforms commenced in 1974 and the unit of currency was standardized to 100 Chhetrum being equal to 1 Ngultrum. Currently coins are available in denominations of Ch.20, Ch.25, Ch.50 and Nu.1.