PNB has more than 70 overseas branches, representative offices, remittance centers and subsidiaries across Asia, Europe, the Middle East, and North America.

Its primary mandate was to provide financial services to Philippine industry and agriculture and support the government's economic development effort.

World War I, then raging in Europe, generated huge demand for the country's major exports, namely sugar, copra, coconut oil, Manila hemp and tobacco.

[citation needed] On February 4, 1916, Public Act 2612 was passed by the Philippine Legislature providing for the establishment of PNB to replace the small ₱1,000,000 (equivalent to ₱494,826,983 in 2021) government-owned Agricultural Bank.

[citation needed] In 1921, the national bank experienced near-bankruptcy due to mismanagement and weak American colonial structure.

[citation needed] PNB briefly ceased operations in January 1942 but reopened the next month under the supervision of Japanese authorities.

After the Second World War, PNB reopened immediately and acquired the assets and assumed the liabilities of the banking division of the Bangko Sentral ng Pilipinas.

In 1963, it established the National Investment and Development Corporation to engage primarily in long-term and equity financing of business ventures.

[citation needed] PNB transferred to its new head office along Escolta in 1966 and launched the first on-line electronic data processing system in the Far East.

[citation needed] Between 1967 and 1979, PNB opened offices in London, Singapore, Jakarta, Honolulu and Amsterdam, and 14 provincial branches.

However, it encountered difficulties in the mid-80s as a result of the economic downturn triggered by the assassination of Senator Benigno S. Aquino Jr. and in 1986 received assistance from the government.

In 1990, Benedicto agreed to turn over ownership of that bank to the Philippine government in return for criminal racketeering and conspiracy charges against him being dropped.

In 1996, the Securities and Exchange Commission approved the bank's new Articles of Incorporation and by-laws and the change in the status of PNB from a government-based to a private corporation with the control of the government reduced to 46 per cent.

[12] PNB has remittance centers in the United States, Canada, England, Spain, the Netherlands, France, Germany, Austria, Italy, Hong Kong, Japan, Singapore, Malaysia and in countries in the Middle East.

The landmark decision would trigger a planned merger between PNB and Tan's own Allied Banking Corporation.

[17] As of July 7, 2010, the remaining stumbling block to the merger was addressed, as the latter found a buyer for its minority stake in a California-based bank.