Today, 160 countries are member states of the BIE.

Membership to the BIE is open to any Government by accession to the 1928 Paris Convention on International Exhibitions:

“This Convention shall be open for accession by any State which is a member of the United Nations, or any State which is not a member of the United Nations but which is a Party to the Statute of the International Course of Justice or any State which is a member of one of the specialised agencies of the United Nations or the International Atomic Energy Agency and also by any State whose application for accession is approved by a two-thirds majority of the Contracting Parties which have the right to vote in the General Assembly of the Bureau. Instruments of accession shall be deposited with the Government of the French Republic and shall become effective on the date they are so deposited.”

1928 Paris Convention, Article 35

The BIE member’s states take part in all of the organization’s deliberations and engage in the development of Expo policies and principles. Member states also participate from the outset in discussions with the Expo organizers, especially as it pertains to their participation.
The status of BIE’s member state also has a number of other benefits.