At least 17,000 people have signed up to take part in legal action against the ANZ over alleged unfair penalty fees.
ANZ customers were given until midnight on Friday to join the action which is the first in a number of cases expected to be taken against the major banks by the Fair Play on Fees group.
Lawyer Andrew Hooker, who is fronting the action, said it was still collating the final sign-up numbers.
"However we can safely say that the final figure for ANZ will be in excess of 17,000 people."
The case is set down for a procedural court hearing in early March and Hooker is hopeful that the full case will be heard in 2014.
"We are certainly pushing it to go to trial next year," he said.
The case alleges that default fees charged by the bank in situations such as unarranged overdrafts, bounced cheques and late and over-limit credit card fees are "unenforceable penalties" and should be paid back to customers.
"The reason that an unarranged overdraft fee on a deposit account is unfair is the same reason that a credit card late payment fee is unfair - these fees are set far above what it actually costs the bank to manage the default that arises," Hooker has previously said.
In its statement of defence the ANZ said that when customers open an account with it they agree to certain terms and conditions including what fees would be incurred for specific "events" such as late payment and unarranged overdrafts.
The bank argued that the fees were not payable as "damages" for breach of the terms and conditions of the ANZ and National Bank accounts.
Rather they were payable when certain "events" occurred within accounts that customers were not entitled to as part of their banking contract.
Hooker has already filed a second case against Kiwibank with the state-owned bank expected to file its defence by March 14.
A third bank target was due to be announced before the end of the year but Hooker said due to the amount of time needed to identify representatives and gather evidence it was now likely to be February.
"It's hugely time consuming."
Meanwhile similar action against the ANZ in Australia has made it to court with the judge expected to make a ruling on it sometime in the next few months.
"We are awaiting that decision with interest, as I am sure the ANZ are," Hooker said.
The New Zealand legal action is being run on a "no win no fee" basis so customers who sign up will have no upfront costs.
Australia litigation firm Slater & Gordon is backing the case which is being funded by Litigation Funding Services.
People wanting to register to join the case can sign up at www.fairplayonfees.co.nz.