The Lisbon Treaty, the latest primary treaty at EU level, was signed on 13 December 2007 and entered into force on 1 December 2009.
The European Union has been given a single legal personality under this Treaty.
Previously, the European Community and the European Union had different statutes and did not operate the same decision-making rules. The Lisbon Treaty ended this dual system.
On practical terms, all EU legislation has the reference to the EU since 1 December 2009. Up till then, the reference was made to the European Community (EC) as only this body had legal personality.