Kiwibank, a wholly-owned subsidiary of state-owned enterprise New Zealand Post, is set to face a class action for penalising customers with unfair penalty fees, according to an initiative, Fair Play on Fees (FPF).

The FPF, which aims to claim back unfair bank fees, will receive financial support from New Zealand-based Litigation Lending Services, while Australian firm Slater & Gordon will provide project management and litigation advice to the case.

Customers have been ordered by FPF to register online at by 21 November 2013 to ensure their inclusion in the case, which will be filed with the court on 22 November.

FPF said they now have a sufficient number of Kiwibank customers to take their complaint to court and fight to get their unlawful penalty fees back.

"We expect thousands more Kiwibank customers to join the campaign as a result of today’s announcement and encourage them to do so before the court documents are filed.

"We also encourage customers of all the remaining banks who have been affected by penalty fees to sign up to the Fair Play on Fees action. Today is also an opportunity for customers of all banks to take a stand against these unlawful fees," FPF added.

More than 35,000 customers have so far signed up with FPF, where over 6,000 from Kiwibank and others from ANZ/National Bank.