From 1 June 2012 the rules contained in EC Regulations 883/2004 and 987/2009 which can affect the National Insurance contributions (NICs) liabilities of people moving between EU Member States or in certain cross border situations will apply to Norway, Iceland and Liechtenstein.
If an individual goes to live or work in Norway, Iceland or Liechtenstein from the above date, then the new rules will apply to both the individual and their employer. Under both the old rules and the new rules, depending upon the circumstances of employment, it may be that the individual continues to pay UK National Insurance contributions whilst there or they may be required to start paying contributions to the country they are in instead.
An important difference between the old rules and the new rules is that if an individual is working in the UK for a Norwegian, Icelandic or Liechtenstein employer and are paying NIC contributions here then their employer may also have to start paying UK contributions. The new rules also apply to self-employed people moving between the UK and Norway, Iceland or Liechtenstein.
More information is available here.