In short term, some project work for actuaries on brexit. In the long term, less opportunities in the UK as some companies are moving business outside of the UK.
In the UK following a hard Brexit? Changes proposed to regulation, in particular, are below. https://www.gov.uk/government/publi...exit-regulations-2018-explanatory-information
And if "no deal brexit" we may be better off finding actuarial opportunities outside of the UK, given the drop of the pound value and who knows what kind of other changes in insurance companies....
In the long term, if Britain leaves the single market it will end passporting rights and mutual recognition of qualifications. As such exports of services will end which is bad for UK insurance and bad for actuarial jobs. However in the short term there will be a glut of jobs created in sorting out the disaggregation of balance sheets and setup of new legal entities. EIOPA have set a three year period of transition for legacy business.