Litigation Lending Services (NZ) is funding the proceedings and will get 25 per cent of what ever Fair Play is awarded.
"If the court rules they [an individual claimant] has paid $1000 too much they'll get $750 back," he said.
Hooker said he though its average claimant had paid $1000 to $1500 in these fees, which are charged for unarranged overdrafts, bounced payments, late credit card payments and going over credit card limits.
Hooker claims the cost to the banks of the transactions is just a few cents compared with the fees of up to $30 being charged.
Hooker said that Queen's Counsel Bruce Gray would take over the ANZ proceedings from here and that he was now going back to his office to work on the case against the next bank.
It was not decided who Fair Play on Fees would take on next, though Hooker said previously that all the major banks including Westpac, BNZ, ASB and Kiwibank are in his sights.
Asked if he was open to settling with ANZ, Hooker replied:
"We're always open to discuss that but ANZ have made it clear they want to run the case so if that's what they want to do then it's entirely in their hands," he said.
More than 32,000 people have registered to join the lawsuit of which 13500 are individual customers of the ANZ and 1800 are small businesses.
The number of people signing up has grown by 7000 since ANZ was named last Tuesday as the first bank to be targeted.
Hooker said earlier today the filing of the court documents against the ANZ marked an important milestone in the case.
"Many people thought the case would not get enough support.
"Today we are here to say New Zealanders are behind the court action. Kiwis want heavy-handed and punitive behaviour from the banks to stop."
The ANZ has said it will vigorously defend the case.
The public are being asked to sign up for the case at fairplayonfees.co.nz.