Australian law strictly limits the number of coins used in single transactions

This law exists to prevent the impractical use of vast quantities of low-value coins in commercial transactions. When Australia transitioned to decimal currency in 1966, policymakers anticipated that businesses and consumers needed protection against someone paying for goods using hundreds of coins. The provision protects merchants from being forced to accept payment methods that would be unreasonably cumbersome to process.

The law has become less relevant with modern payment systems, but it remains important for transactions in cash-only situations or informal commerce. For example, one cannot legally pay for a A$20 item using only 5-cent coins (which would require 400 coins). The Reserve Bank of Australia maintains these regulations to ensure commerce can flow efficiently while still respecting coins as legal tender for reasonable payment amounts.