People have a low level of knowledge when it comes to privacy and their bank accounts, according to an independent bank complaints scheme.
The Banking Ombudsman Scheme has looked into 26 privacy and confidentiality related cases since July last year and 44 in its previous financial year.
Deborah Battell, the Banking Ombudsman, said some cases showed failings in bank procedures and typically banks compensated their customers when that occurred.
"But others indicate people generally have a low level of knowledge about what privacy means in a banking context."
Battell said one of the most common misconceptions was around the difference between privacy and confidentiality.
"It's really around what privacy means."
Top bank privacy complaints:
*giving information to someone complainant believed was not entitled to it (39 per cent)
*declining to provide personal information the complainant believed they were entitled to (38 per cent)
*allegations a bank officer had accessed personal information for their own or others' benefit (13 per cent)
*requiring information which the complainant considered to be personal or refusal to delete personal information (10 per cent)
While banks had a duty of confidentiality there were some situations where a bank could legally give out information.
These included where the bank was compelled by law to give out information such as providing details to the Inland Revenue, Ministry of Social Security or a liquidator about a business in liquidation.
Banks also have to report suspected money laundering to the police and may have a public duty to disclose information if there is a danger to the state or where the wider public needs protection against crime.
A bank may have to disclose information to protect its owns interests when it takes legal action against a customer.
Information can also be given to others if a customer agrees for that to happen.
The biggest cause (39 per cent) of privacy complaints and inquiries to the scheme was around banks giving information to someone which the complainant did not believe was entitled to it.
A further 38 per cent of cases related to people complaining the bank declined to provide personal information they believed they were entitled to.
In 13 per cent of cases the complainant alleged a bank officer had accessed personal information for their own or others' benefit.
The remaining 10 per cent of cases involved people complaining about banks requiring information which the person considered to be personal or refusal to delete personal information.
Where information was given to those who complainants said were not entitled to it, the information was typically given to a relative, former partner or employer.
Information included bank account numbers, balances, contact details.
Battell said some of the problems arose around joint accounts when people split up and relationships broke down.
Where the bank declined to provide information this was typically to those who were not named on the account and therefore not entitled to the information.
This had occurred in some situations where a complainant was related to someone who died.