The High Court of Australia last week dealt a blow to the big four banks when it overturned a Federal Court ruling and found that certain fees charged by banks -- specifically honour, dishonour, non-payment and over-limit fees -- could be classified as "penalty fees".

Federal Court justice Michelle Gordon had erroneously found those fees weren't able to be deemed penalties (effectively limiting the action only to "late-payment fees"). The former tax lawyer's decision was roundly overturned by a unanimous High Court bench.