What does AU mean?

AU in finance typically stands for "Authorization." In the context of financial transactions, AU refers to the process by which a cardholder's bank approves or declines a transaction. When a cardholder makes a purchase, the merchant sends an authorization request to the cardholder's bank to verify that the card is valid and that the cardholder has sufficient funds to cover the transaction. The bank then either approves or declines the transaction and sends a response back to the merchant. This authorization process is an important part of ensuring the security and validity of financial transactions. Additionally, AU can also refer to "Australasian units," a unit of measure used in the trading of precious metals in the Australian and New Zealand financial markets.