On 1 March 2010, initial guidance1 was released by the U.K.s HM Revenue & Customs HMRC on the practical implementation of the new European Union EU social security rules, effective 1 May 2010, as contained in Regulations EC 883/2004, 987/2009, and 988/2009.2 It is expected that in the coming weeks HMRC will issue further comments in the form of frequently asked questions and that the social security authorities in other member states will issue their practical guidance.