Which countries are inside the EU?

The following countries are inside the EU: 

Austria, Belgium, Bulgaria, Croatia, Republic of Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania,Luxembourg, Malta, Netherlands, Poland, Portugal,Romania,Slovakia, Slovenia, Spain, Sweden and the UK.

What documents do I need to send inside the EU?

What documents do I need to send outside the EU?