This list only covered those complaints which required mediation.
Complaints going to the ombudsman were again dominated by worries over the sale of Payment Protection Insurance (PPI).
Most complained about groups
- Lloyds Banking Group: 22,181 (22,420 in previous six months)
- Royal Bank of Scotland: 8,644 (6,469)
- Barclays: 8,256 (9,215)
- HSBC: 8,238 (4,031)
- Santander: 6,759 (5,372)
There were 22,181 complaints about Lloyds Banking Group, of which 12,234 were specifically about Lloyds TSB - the most of any single business.
Five financial services brands - Lloyds TSB, Royal Bank of Scotland, Barclays, HSBC and Santander UK - had more than 6,000 complaints about them received by the ombudsman.
"The latest set of complaints data continues to show that while some financial businesses are improving the way they handle their customers' complaints, some regrettably are not," said chief ombudsman Natalie Ceeney.
"Taking the trouble to handle complaints well is an important part of a business's ongoing relationship with its customers - and it is the key to providing really excellent customer service."
The ombudsman accepted that the size of the business would affect the complaints levels.
However, when it consulted with experts on how this should be taken into account in the figures, they disagreed, so the figures are published in their raw form with no adjustment for size.
Of the large banking groups, there were increases in complaints to the ombudsman from customers of Royal Bank of Scotland, HSBC and Santander, compared with the first six months of the year.