The Financial Ombudsman Service (FOS) has released new figures breaking down the 106,193 complaints it received in the last 6 months of 2011.

With nearly 12,000 complaints during this period, Barclays was the worst performing bank.

From 1st July to 31st December, the FOS handled 11,524 complaints about Barclays. In 84% of cases, the FOS upheld customers’ grievances. 6,975 complaints related to mis-sold PPI, whilst 3,474 related to banking and credit. The rest involved a range of products and services including investments and mortgages.

There were a total of 20,310 complaints during that period regarding the Lloyds Banking Group, which owns Lloyds TSB, Cheltenham & Gloucester, the Bank of Scotland and Halifax.

PPI complaints accounted for 46,700 cases dealt with by the FOS in the second half of 2011. This was down more than 50% on the number of complaints received in the first half of the year, but, at present, the ombudsman is receiving around 1,000 complaints every day, with this figure expected to increase. In 2012/13, the ombudsman anticipates 165,000 complaints about PPI.

Overall, 72% of PPI complaints were upheld in the second half of 2011, compared with 47% in the first half of the year. This is because the vast majority of PPI complaints are being upheld.

Chief ombudsman Natalie Ceeney indicated that whilst some banks had made an effort to resolve PPI complaints quickly and fairly, others had been less proactive, stating “we now hope to see all businesses who were involved in PPI mis-selling resolving their customer’s complaints fairly, properly and quickly.”