More than 70 complaints about how banks deal with the accounts of dead customers have been made to the Banking Ombudsman this year.
The figure was revealed to the Herald after several widows said joint credit cards and accounts they shared with their husbands were cut off without warning after they died, leaving some women in tears.
ANZ, ASB and Westpac have all apologised for providing poor service to the women.
Grieving pensioner Gabrielle O'Callaghan lost access to her money after Westpac Bank stripped her of her credit card and closed an account following her husband's death.
Westpac Bank apologised and said it "highlighted a gap in the way that we handle our deceased estates".