The penalty is the biggest in Australian corporate history, and is almost double the previous record $700 million fine paid by the Commonwealth Bank for almost 54,000 money laundering breaches, revealed by the ABC in 2017.
In a statement, AUSTRAC said Westpac had admitted to breaching the Anti-Money Laundering and Counter-Terrorism Financing Act more than 23 million times.
Australian Transaction Reports and Analysis Centre (AUSTRAC) is responsible for picking up criminal abuse of the financial system in Australia.