Why doesn the UK, Sweden and Denmark use the Euro?
The United Kingdom has a derogation to the original Maastricht Treaty, establishing the Euro. Unless approved by the Cabinet, Parliament and British electorate in a referendum, the UK can opt out of joining the Euro zone. The same situation applies to Denmark, though a referendum put to the Danish electorate in December, 2000, showed a 53.2% majority oppose joining the Euro zone. Unlike the UK and Denmark, Sweden has no such derogation to the Maastricht Treaty and therefore is expected at some point in the future to adopt the Euro. There are several proposals for designs of the Euro for these countries. Denmark has already chosen the design of its Euro coins if and when a future referendum passes.
