More than 19,000 people submitted cases in 2012, compared with just over 11,000 in the previous year, the Financial Services Compensation Scheme (FSCS) said.
The number of people making claims for mis-sold payment protection insurance (PPI) from firms which have gone bust has almost doubled year-on-year, figures show.
The share of people using claims management companies (CMCs), which typically take a quarter of any payout, dropped to 59% in 2012, from 76% the previous year, the FSCS said.
The average payout to people who brought their own claim in 2012 was almost £4,895, compared with £3,837 to those who used a CMC.
However, the share of complaints which were upheld in consumers' favour was slightly higher in cases when a CMC was used last year, at 82%, compared with 73% when someone had brought a case themselves.
The FSCS, which is funded by an industry levy, can pay out compensation to consumers who have been mis-sold PPI in cases when the company which sold the policy has gone under.
The safety net said that it has paid out almost £136 million for PPI claims since 2008 - but it also estimates that consumers paid more than £22 million of their compensation to claims management firms.
Mark Neale, chief executive of FSCS, said: "Claims management companies take a sizeable chunk of any payout. 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 findings come after the Financial Ombudsman Service, which resolves disputes between people and financial services firms, recently reported that it handled a record 11,000 complaints a week about PPI mis-selling in the last three months of 2012.