The Financial Ombudsman Service (FOS) is currently upholding about 47% of all complaints, according to the FOS' own figures.
Data for the three months to December 2012 show the vast majority of complaints - 145,546 out of 180,679 in total - relate to payment protection insurance (PPI).
That takes the total number of PPI complaints for last year to 244,873. The FOS said it is currently taking on between 8,000 and 10,000 new PPI complaints each week, meaning it expects to receive more than 350,000 PPI complaints this year.
So far this financial year - from last April - the FOS has found in the consumers favour in 62% of PPI cases, down from seven out of ten complaints.
The ombudsman has received 341,666 new complaints across all products since April 2012, and received more complaints in the last quarter than in any year between 2000 and 2010.
Mortgage endowments accounted for 3,367 complaints in the year to date since April. Whole of life policies made up 1,893.
Complaints about personal pensions were at 1,537 for the year to date from April. Portfolio management complaints totaled 1,173 for the same period.