Consumer NZ is concerned a proposed new banking code of practice will no longer have a key protection for bank clients.
The current code says banks will reimburse the victims of genuine fraud.
But the draft code, which the New Zealand Bankers Association proposed in June 2017, plans to scrap that principle and instead give banks the freedom to set their own policies regarding fraud reimbursement.
But the Bankers Association says it's rewriting the code to simplify it - not to lessen consumer protection.
The association has also been criticised for not releasing any of the feedback it received on the code, despite the deadline for public submissions closing more than six months ago.
The new code should be published within the next few months.