In the financial year to April 2018, the FCA spent £1.8m and it expects to spend a further £2.1m in the current financial year.
According to data released following a Freedom of Information request, the biggest charge was on internal resource and programme management which cost the regulator about £1.3m.
It also spent £264,000 on IT system changes, while external consultancy and legal advice cost the watchdog £235,826.
A further £84,575 was spent on staff training, with one employee recruited. This year the regulator plans to recruit two further staff members but will reduce training costs to around £60,000.
The FCA confirmed a forecasted budget of more than £2m to tackle the challenges in the current financial calendar running to April 2019.
While it plans to spend the same amount in consultancy and programme management this year, it will be spending £49,000 in compliance software and £177,600 in external consultancy and legal advice.