On 9 April 2018, the FCA published a consultation paper on its fee proposals for 2018/19 (CP18/10).
The FCA explains that for 2018/19 its annual funding requirement (AFR) will be £543.9 million. This is an increase of £17 million  over last year.  No surprises there for an organization that in 2002 was spending just £181 million.  
To be fair the levy includes payment for the Financial Ombudsman Service (FOS), the Money Advice Service (MAS), the Pension Wise service and HM Treasury's illegal money lending expenses.  In addition the FCA also now regulate credit, mortgages and general insurance.