Maurice Blackburn senior associate Paul Gillett said the documents would seek leave for an appeal to be heard before the full bench of the Federal Court.

“In her ruling Justice Gordon said that late payment fees were charged when a customer breaches a term of their contract with ANZ and, as a result, those fees must reflect a reasonable pre-estimate of the loss actually caused to ANZ by a late payment on a credit card account,” Gillett said.

“We know that banks have charged $20 or $30 for late payment fees on credit cards. It is now clear that if the cost to ANZ is only a fraction of that amount, our clients will be entitled to a refund of those late fees. However, her Honour did not make the same ruling for honour, dishonour and overlimit fees. It is this part of the decision that we are appealing.

“We will also argue that her Honour should have applied a broader test of when a fee can be a penalty: a test that does not first need to establish a breach of contract.”

Maurice Blackburn this month issued proceedings against another four banks expanding the number of people involved in the class action to 150,000 Australians.

Proceedings against ANZ, NAB, Commonwealth Bank, Westpac and Citibank are now underway.

“Tens of thousands of people have joined the class action, which is the biggest in Australian history. We have said from the start that this action is about bringing fairness to all bank customers,” Gillett said.

The ANZ appeal is likely to be heard in the early part of 2012. Bank fees class actions launched in December in the Federal Court against NAB, Westpac, Citibank and Commonwealth Bank are due back in court for a first directions hearing on Friday 9 March 2012.