Mortgage brokers will see their regulatory fees rise by 33% from £745 to £1,000 and AMI said the increase is disproportionate.
Robert Sinclair, director of AMI, called for a review of how the regulator decides on its costs.
He said: “We are struggling to identify the need for a 33% increase in costs for a sector that has shrunk to a fraction of its previous size. The increase of 10% is more than seven times the current rate of inflation.
“It was not the intermediary world that caused this crisis, but we appear to be picking up the tab. The intermediary sector does not present the same risks as the banking and wholesale sectors.”
Sinclair said that the network model will mean that small firms will be penalised severely as they will suffer large increases due to the success of their parent organisation.
He added: “There are more appropriate risk indicators than the size of the firm and the FSA needs to consider this further. Fees must take account of the sector the firm operates in, particularly those that operate strong compliance cultures, and the overall systemic risk that sector poses to the economy.”