Organisers of a proposed lawsuit against the country's banks say more than 11,000 people have signed up to the class action since launched it on Monday.
New Zealand lawyer Andrew Hooker, Australian class action experts Slater & Gordon and Litigation Lending Services are leading the Fair Play on Fees campaign.
They say up to one million New Zealanders could be eligible to claim back excessive default fees, estimated to be around $1 billion over the past six years.
The group has reached the minimum number of people needed to take the class action and is anticipating at least another 9000 people will sign up in the next day.
