Parliament has passed legislation under urgency removing the right of beneficiaries to claim back payments for an error in the law that has been in place for 18 years.
The error has meant that since 1998 Work and Income has paid most benefits a day late.
The bill changes the law to retrospectively change the payment date to the day after stand-down and effectively to wipe the debt.
The legislation passed its third and final reading by 75 votes to 46, with the Labour and Green Party opposing it.
