| Flag | State | Official name | Accession | Population | Area | Capital | MEPs |
|---|---|---|---|---|---|---|---|
| Austria | Republic of Austria | 1 January 1995 | 8,316,487 | 83,871 | Vienna | 18 | |
| Belgium | Kingdom of Belgium | 25 March 1957 | 10,584,534 | 30,528 | Brussels | 24 | |
| Bulgaria | Republic of Bulgaria | 1 January 2007 | 7,679,290 | 110,912 | Sofia | 18 | |
| Cyprus | Republic of Cyprus | 1 May 2004 | 766,400 | 9,251 | Nicosia | 6 | |
| Czech Republic | Czech Republic | 1 May 2004 | 10,306,709 | 78,866 | Prague | 24 | |
| Denmark | Kingdom of Denmark | 1 January 1973² | 5,457,415 | 43,094 | Copenhagen | 14 | |
| Estonia | Republic of Estonia | 1 May 2004 | 1,342,409 | 45,226 | Tallinn | 6 | |
| Finland | Republic of Finland | 1 January 1995 | 5,289,128 | 338,145 | Helsinki | 14 | |
| France | French Republic | 25 March 1957 | 63,392,140 | 674,843 | Paris | 78 | |
| Germany | Federal Republic of Germany | 25 March 1957¹ | 82,314,906 | 357,050 | Berlin | 99 | |
| Greece | Hellenic Republic | 1 January 1981 | 11,125,179 | 131,990 | Athens | 24 | |
| Hungary | Republic of Hungary | 1 May 2004 | 10,066,158 | 93,030 | Budapest | 24 | |
| Ireland | Ireland | 1 January 1973 | 4,239,848 | 70,273 | Dublin | 13 | |
| Italy | Italian Republic | 25 March 1957 | 59,131,287 | 301,318 | Rome | 78 | |
| Latvia | Republic of Latvia | 1 May 2004 | 2,281,305 | 64,589 | Riga | 9 | |
| Lithuania | Republic of Lithuania | 1 May 2004 | 3,373,991 | 65,303 | Vilnius | 13 | |
| Luxembourg | Grand Duchy of Luxembourg | 25 March 1957 | 476,200 | 2,586 | Luxembourg | 6 | |
| Malta | Republic of Malta | 1 May 2004 | 404,962 | 316 | Valletta | 5 | |
| Netherlands | Netherlands | 25 March 1957 | 16,372,715 | 41,526 | Amsterdam | 27 | |
| Poland | Republic of Poland | 1 May 2004 | 38,116,486 | 312,683 | Warsaw | 54 | |
| Portugal | Portuguese Republic | 1 January 1986 | 10,599,095 | 92,391 | Lisbon | 24 | |
| Romania | Romania | 1 January 2007 | 21,565,119 | 238,391 | Bucharest | 35 | |
| Slovakia | Slovak Republic | 1 May 2004 | 5,396,168 | 49,037 | Bratislava | 14 | |
| Slovenia | Republic of Slovenia | 1 May 2004 | 2,013,597 | 20,273 | Ljubljana | 7 | |
| Spain | Kingdom of Spain | 1 January 1986 | 45,116,894 | 506,030 | Madrid | 54 | |
| Sweden | Kingdom of Sweden | 1 January 1995 | 9,142,817 | 449,964 | Stockholm | 19 | |
| United Kingdom | United Kingdom of Great Britain and Northern Ireland | 1 January 1973 | 60,587,300 | 244,820 | London | 78 |
Source: Wikipedia
1 On 3 October 1990, the constituent states of the former German Democratic Republic acceded to the Federal Republic of Germany, automatically becoming part of the EU.
2 Greenland left the Community in 1985.