As many as 20 of the biggest international asset managers and custody banks have received the requests as part of the FCA’s information-gathering.
The FCA wants to know how firms are planning ahead of the UK leaving the EU so it can work out its own response.
The City regulator was keen to point out the questions are not part of a formal or systematic exercise, and will only be used to deepen their understanding of the challenges posed by Brexit to the industry.
The list of questions only went out to firm that are solely regulated by the FCA. The Prudential Regulatory Authority, which has oversight over broader financial stability issues, has also asked the firms it regulates for similar information.
The firms will be asked to provide information on their contingency plans on a wide variety of issues, including their capital base and their IT systems, according to the Financial Times.
An FCA spokesperson said: “It is important for us as supervisors to understand the plans that our regulated firms have regarding Brexit.
“To help firms prepare for these conversations, we shared the details of the questions we would be asking. This was not a formal data request and was not asking firms to undertake any further work.”