Between 1 July and 31 December 2010, the ombudsman received a total of 97,237 new complaints, compared to 84,212 in the first half of 2010.

According to the report, Lloyds tops the list with 22,181 complaints received during second half of the 2010, Royal Bank of Scotland stood second with 8,644 complaints followed by Barclays with 8,256.

Ombudsman said that the data published covers consumer complaints handled by it during second half of 2010 and it includes both the number of complaints received about individual businesses and the percentage of complaints upheld by the ombudsman service in favor of consumers.

The number of new complaints about each of the individual businesses ranged from 30 to 12,234. Five financial services groups had over 6,000 complaints each referred to the ombudsman service, which together accounted for 54,078 cases, over half of all the new complaints received by the ombudsman during this six-month period.

The data published shows that in the second half of 2010 the ombudsman service upheld an average of 53% of complaints in favor of consumers, compared to 44% in the first half of 2010.

Across the 162 individual businesses included in the complaints data, the uphold rates varied substantially between 5% and 95% upheld in favor of consumers.

Financial Ombudsman Service chief and chief executive Natalie Ceeney said 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.

"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," Ceeney said.