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.

港幣（HKD）是香港特別行政區的流通貨幣，首張港幣由東方匯理銀行發行於1845年，距今已經超過179年。港元採用聯繫匯率制度，最初與英鎊掛鉤，但1972年6月英鎊改為自由浮動制後，港府決定將港幣改為與美金掛鉤，並延續至今。港府設定的浮動範圍在1美金兌7.75到7.85港元之間，如果匯率超出此范圍，金管局將出手干預，以維持穩定。在本港的找換店行業，港幣最經常兌換的外幣包括人民幣、日元、菲律賓披索、印尼盾以及美金。