As the name suggests, this currency was initially used for customs payments, but in 1942 it was put into general circulation for use by the public at 20 times its face value in terms of the first Chinese yuan.

The CGU's value, fixed against the US dollar, fluctuated against the Chinese yuan, based on the current yuan–dollar and yuan–sterling market exchange rates.

In practice, the customs gold unit lost all its special features and simply became equivalent to 20 Chinese legal tender dollars (CGU1 = CNC$20).

When Nationalist troops and officials arrived in Shanghai in 1945, they brought with them newly printed notes of 20 and 50 customs gold units.

The back of some of the notes bore the following English text preceding the denomination: "The Central Bank of China promises to pay the bearer on demand at its office here."