The Financial Ombudsman Service has added an extra £3m to its final annual budget for 2013/14 since it consulted in January, bringing the total to £283.6m.
The figure represents a 93 per cent increase on this year’s £147.2m budget.
The FOS initially set its budget at £280.1m, but last week approved a final budget of £283.6m.
Most of the cost burden for 2013/14 will fall on the largest firms like banks, which from April will pay a new quarterly group account fee, rather than a standard case fee.
Standard case fees for other firms will increase from £500 to £550, and the number of free cases from three to 25. Both measures will be introduced in April.
The FOS also charges a £350 supplementary case fee for payment protection insurance complaints.
The difference in the budget from January compared to the final budget was driven by lower than expected income from case fees and supplementary case fees.
The FOS levy on financial services firms will go up 30 per cent from £17.7m to £23m.
Highclere Financial Services partner Alan Lakey says: “It disturbs me greatly that an organisation like the FOS can decide its budget is going to jump up and the people who pay the bill have no choice in the matter.”
Separately the FOS has set out its approach for publishing ombudsman decisions, which it will be required to do from 1 April. Firm names will be published but not the name of the complainant.