The Banking Ombudsman Scheme received 16 per cent more cases in the past financial year, refuting expectations that the use of the scheme would decrease as consequences of the global financial crisis eased.
Banking Ombudsman Deborah Battell said while global financial crisis (GFC) related complaints were down, contact with the Banking Ombudsman remained high due to public interest in legislative changes including anti-money laundering legislation, bank fees litigation and the ANZ/National bank merger.
Complaints from small businesses also increased - making up just over one in 10 complaints, Battell said.
"While the GFC is no longer affecting personal banking customers, it appears small business are still feeling its lag effect."
The Banking Ombudsman Scheme's Annual Report for 2012/13 showed nearly a third of dispute cases in the past financial year resulted in a favourable outcome for customers, either partially or in full.
Compensation for customers increased to $598,000 in 2012/13 from $505,139 the previous year.
The Ombudsman received an 82 per cent spike up in enquiries about Kiwibank in the year to June 30 although this did not translate into higher complaint or dispute numbers for the state-owned bank.
Enquiries - where a customer seeks advice about a particular issue or information on how make a complaint - increased from 100 to 182 for Kiwibank.
Numbers of complaints fell from 98 to 78 and disputes were down from eight to seven. But total cases for Kiwibank made up 10.3 per cent of the total despite its share of banking assets being only 3.8 per cent.
That was up from 9.2 per cent in the prior financial year.
Battell said the scheme was watching the shift away from the previous close correlation between a bank's market share (measured by its share of total bank lending) and the number of cases the scheme received.
"When we first started comparing a bank's market share with the cases we received, we found that there was a close correlation between the two.
"If a bank had, say, 20 per cent of the market share, it generally had about 20 per cent of the share of cases we received."
The trend was changing, along with the balance between large and medium-sized banks, Battell said.
"Large banks accounted for a smaller percentage of cases last year - down from 84.6 per cent to 81.7 per cent, compared with 88.4 per cent of the market.
"Medium-sized participants, whose market share is 11.4 per cent accounted for 17 per cent of cases compared with 14.4 per cent last year."
The changes could be attributed to a number of factors, including banks improving their customer service and complaints-handling processes, Battell said.
-with Tamsyn Parker