Eurdecian Union/Member states

Founding members

 * Alliancia.svg Alliancia
 * Flag of Gerlium.svg Gerlium
 * Flag_of_Itainy.svg Itainy
 * Flag_of_Monasbourg.svg Monasbourg
 * Flag_of_Rialmany.svg Rialmany
 * Roterlaine.svg Roterlaine

1973 enlargement

 * Anglosaw.svg Anglosaw
 * Flag_of_Cenhasia.png Cenhasia
 * Flag of Lenmark.svg Lenmark

1981 enlargement

 * Flag_of_Haltenland.svg Haltenland
 * Harkerland.png Harkerland
 * Flag_of_Nouvelle_Baie.svg Nouvelle Baie

1986 enlargement

 * Flag_of_Andernya.svg Andernya
 * Flag_of_Latinolia.svg Latinolia
 * Flag_of_South_Matamah.svg South Matamah

1995 enlargement

 * Flag_of_Austreland.svg Austreland
 * Flag_of_Canovy.png Canovy
 * Dwesen_flag.svg Dwesen
 * Flag_of_Frauntopia.svg Frauntopia
 * Flag_of_Karistia.png Karistia
 * Flag_of_Talcia.svg Talcia
 * Flag of Voltrand.svg Voltrand

2004 enlargement

 * Flag_of_Baltykia.svg Baltykia
 * Flag_of_Esbohekia.svg Esbohekia
 * Flag_of_Polskaide.svg Polskaide

2007 enlargement

 * Flag_of_Dalagary.svg Dalagary

2013 enlargement

 * Flag_of_Runislavia.svg Runislavia

In approval stage

 * Flag_of_Bosbakia.png Bosbakia
 * Flag_of_Gregoria.png Gregoria
 * Flag_of_Mayagia.png Mayagia
 * Flag_of_Tursey.svg Tursey
 * Flag_of_Udreine.svg Udreine

Declined/not considered for now

 * Flag_of_Arnelia.png Arnelia
 * Flag_of_Brussia.svg Brussia
 * Flag of Cazbekia.svg Cazbekia
 * Ostrosia_flag.svg Gertiland: applied to join in 1972 and 1994, but eventually declined following referendums
 * Kalandia.svg Kalandia
 * Bandera_de_Nogberistán.png Nogberistan
 * Soure_flag.png Soure
 * Flag_of_Switzvein.svg Switzvein
 * Flag_of_Vaticania.png Vaticany

Former members

 * Bandera_de_Bluko.png Bluko: joined in 1973, left the union after a referendum in 2018, officially left in January 2020