The European Economic Area (EEA) includes the following countries:
United Kingdom (UK)
Gibraltar - for everything except healthcare and child benefits, the UK applies the EC Regulations to Gibraltar as though it is another EEA country. Other EEA countries treat Gibraltar as though it is part of the UK.
Switzerland is not a member of the EEA, but as a result of an agreement with the European Union (EU), EU rules on social security will also largely cover Switzerland.