Entry into force and application
Article 4
This Regulation shall enter into force on the day following that of its publication in the Official Journal of the European Union . It shall apply from the date following that on which the Treaties cease to apply to and in the United Kingdom pursuant to Article 50(3) of the Treaty on European Union. However, this Regulation shall not apply in any of the following cases: (a) a withdrawal agreement concluded with the United Kingdom in accordance with Article 50(2) of the Treaty on European Union has entered into force by that date; (b) a decision has been taken to extend the two year period referred to in Article 50(3) of the Treaty on European Union.