From April 6th 2012, HMRC are amending the rules with regards to transfers of uk pensions to overseas schemes. One of the biggest effects will be the closer monitoring of individuals who are living in low tax environments such as Monaco.
It may be more difficult to obtain tax free withdrawals from an overseas scheme post April (although not impossible), and HMRC will know about these withdrawals made. In order to ensure the tax free status of any withdrawal (which is not reportable to HMRC), which for example could be 50% of any pension fund from a regulated EU pension; any transfer to an overseas scheme, and payment needs to be completed by 5/4/2012.