Bank of China Ltd. engages in the provision of banking and financial services. It operates through the following business segments: corporate banking, personal banking, treasury operations, investment banking, insurance, and others.

Although it is not a central bank, the Bank of China is licensed to issue banknotes in two of China's Special Administrative Regions. Until 1942, the Bank of China issued banknotes in mainland China on behalf of the Government of the Republic of China. Today, the Bank issues banknotes in Hong Kong and banknotes in Macau (under the Portuguese name "Banco da China, Sucursal de Macau"), along with other commercial banks in those regions.

The Bank of China was founded in 1912 by the Republican government as China's central bank, replacing the Qing Dynasty's Ta-Ching Government Bank. It has been the second oldest bank in China still in existence after the Bank of Communications, founded in 1908. From its establishment until 1942, it issued banknotes on behalf of the Government along with the "Big Four" banks of the period: the Farmers Bank of China, Bank of Communications and Central Bank of the Republic of China. After the People's Republic was established in 1949, it has become a national commercial and foreign exchange professional bank. Its original central bank designation was carried on by the newly formed People's Bank of China.

As of 31 December 2019, it was the second-largest lender in China overall and ninth-largest bank in the world by market capitalization value, and it is considered a systemically important bank by the Financial Stability Board. As of the end of 2020, it was the fourth-largest bank in the world in terms of total assets, ranked after the other three Chinese banks.

In Global 2000 2022 list of Forbes, BOC was ranked 37 in Sales, 13 in Profit, 5 in Assets, and 112 in Market value.

According to Wikipedia; Forbes