The United States Dollar (USD) is the official currency of the United States, first issued in 1792. It is identified by the ISO 4217 code USD and is commonly represented by the symbol $. The authority for issuing US dollars lies with the United States Department of the Treasury. Currently, circulating US dollar banknotes include denominations of 1, 2, 5, 10, 20, 50, and 100 dollars, along with coins in denominations of 1, 5, 10, 25, 50 cents, and 1 dollar. The U.S. Dollar ranks first globally in terms of trading volume, comprising 88.3% of the total global foreign exchange transactions. Local money changers in Hong Kong all offer the buying and selling of U.S. Dollars.

The Singapore Dollar (SGD) is the official currency of Singapore, first introduced in 1967. It is identified by the ISO 4217 code SGD and is commonly represented by the symbols $ or S$. The issuance and management of the Singapore Dollar are overseen by the Monetary Authority of Singapore. Commonly used banknote denominations include 2, 5, 10, 50, and 100 dollars. Additionally, there are coins in denominations of 5 cents, 10 cents, 20 cents, 50 cents, and 1 dollar. All money changers in Hong Kong facilitate the buying and selling of Singapore Dollar.