The Tổng Đốc had the authority to give permits to Chinese merchants to create foundries in Sơn Tây to produce zinc cash coins that bear the inscription Tự Đức Thông Bảo, but these Chinese merchants may not produce more than a thousand strings of cash at a time.

In many places like in Hanoi the government resorted to purchase copper utensils from the population in order to produce a sufficient number of cash coins for the economy.

Around 1871 various bands of pirates and the Zhuang bandit group the Black Flag Army started taking over the mines of Northern Đại Nam causing the price of all metals to inflate leading to the cessation of the production of zinc cash coins in Đại Nam while copper had to be imported from other countries to continue to produce Tự Đức Thông Bảo cash coins.

After the government started increasing the exchange rates between zinc and copper while lowering the copper content of the brass cash coins the people started hoarding all the "good coins" or melting them down to make utensils which was publicly denounced by the minister of finance Ngụy Khắc Tuần.

[11] As the government didn't produce enough money for the Vietnamese market it permitted the private production of cash coins and deliberately dissolved its own monopoly on the creation of zinc and brass Tự Đức Thông Bảo cash coins as a measure to increase the national money supply.

Around this time a large amount of counterfeit Tự Đức Thông Bảo cash coins of inferior were being produced abroad, especially in the Qing dynasty provinces of Guangdong and Guangxi as well as in Macau, Hong Kong, and Cochinchina.

[13] During the Tự Đức period the zinc Tự Đức Thông Bảo was both the smallest denomination and the base of the entire currency system, the zinc cash coin had become legal tender in every province of Đại Nam since the beginning of the Nguyễn dynasty and under the reign of Emperor Minh Mạng was standardised at a weight of 6 phần.

The brass currency of previous dynasties that circulated in Đại Nam prior to the introduction of these zinc coins completely disappeared from the market.

Zinc cash coins have always been a major source of irritation for the government as they were very heavy compared to their intrinsic value making them difficult to transport in larger quantities and were also weak and easily damaged due to their brittle nature.

[11] The brass Tự Đức Thông Bảo cash coins started being produced during the first year of the reign of Emperor Tự Đức, under the preceding emperors Minh Mạng and Thiệu Trị there were brass cash coins of 6 phần and 9 phần cast.