State Finance Minister Courtney Houssos on Wednesday revealed two government agencies – Revenue NSW and Service NSW – had charged about $144 million in merchant fees since 2016 across 92 million card transactions.

The payments were charged despite the practice being flagged as unlawful in legal advice received from the Crown Solicitor’s Office on three occasions between February 2016 and December 2022, Houssos revealed on Wednesday.

The payments are largely small. Renewing a driver’s licence for three years costs $162. The merchant fee on that transaction would amount to about 71 cents, the government said. Houssos said modelling had shown that over the eight years in which the charges were in place, the average person would have paid about $30 in unlawful fees.

However the government said it could not commit to refunding the illegal payments, in part due to the complexity of identifying who had paid what as a result of privacy stopgaps in online payment systems. Dib said the government was “working on a number of different potential strategies”.