1 - Denmark - has not introduced the euro, following a rejection by referendum in 2000, but the Danish krone is pegged closely to the euro in ERM II.
2 - UK - As a member of the European Union, the United Kingdom could adopt the euro as its currency.
3 - Sweden - According to the 1995 accession treaty, Sweden is required to join the eurozone and therefore must convert to the euro at some point.
4 - Czech Republic - planned to adopt the euro in 2010, but its government suspended that plan indefinitely in 2005.
5 - Hungary - As a member of the European Union, the long term aim of the Hungarian government may be to replace the forint with the euro but that does not appear to be likely until some time during the 2020s.
6 - Poland - Conditions of Poland's joining the European Union (in May 2004) oblige the country to eventually adopt the euro, though not at any specific date and only after Poland meets the necessary stability criteria. Serious discussions of joining the Eurozone have ensued. However, article 227 of the Constitution of the Republic of Poland will need to be amended first, so it seems unlikely that Poland will adopt the euro before 2019.
7 - Bulgaria - gained EU membership in 2007 various dates have been suggested as the expected end of the lev: towards the end of that year 1 January 2012 was a possible date.
8 - Romania's - Convergence Report set a target date of 1 January 2019 for euro adoption.
9 - Croatia - The country joined the European Union on 1 July 2013 and it plans to join the European Monetary System. Kuna is expected to be replaced by the euro within two or three years after joining the European Union.
Very different reasons for each country NOT using the Euro currency. These are the only (9) countries that do not use the EURO yet. The European Union (EU) comprises 28 member states.
The British Empire has always been and continues to be evil. However, they have never been stupid. They know exactly what they are doing and there is a reason why they are leaving the EU now.