More than 19,000 people submitted claims in 2012, up from just over 11,000 in the previous year.
59% of claims in 2012 came from claims management companies and were worth more than £29m.
With CMCs typically taking a commission of 25% of the compensation UK consumers paid more than £7.4m for a service they could have received for free.
Mark Neale, chief executive of FSCS, said: "Claims management companies take a sizeable chunk of any pay-out.
“Consumers who make a claim directly to FSCS keep every penny of their compensation.
“Some people may prefer to use a claims management company, but it is important that they understand the charges from the outset and are happy to pay them.”
The FSCS has paid out almost £136m in mis-sold PPI claims since 2008 with over £89m going through claims management companies.