thumb|500px|World Customs Organization members and WCO regions in 2010:

As of January 2023, the World Customs Organization has a total of 186 members.

East and Southern Africa

  • United Nations member states
  • — 1990-09-26
  • — 1978-08-25
  • — 1964-10-20
  • — 1993-07-01
  • — 2008-03-19
  • — 1995-08-08
  • — 1981-05-15
  • — 1973-08-06
  • — 1965-05-24
  • — 1978-08-02
  • — 1964-02-18
  • — 1966-06-06
  • — 1973-03-29
  • — 1987-07-01
  • — 1992-07-01
  • — 1964-03-03
  • — 2000-07-25
  • — 2012-10-04
  • — 2012-07-18
  • — 1964-03-24
  • — 1964-11-07
  • — 1964-11-03
  • — 1978-09-27
  • — 1981-03-19

Europe

  • United Nations member states (founders in bold)
  • — 1992-08-31
  • — 1998-09-03
  • — 1992-06-30
  • — 1953-01-21
  • — 2000-02-10
  • — 1992-06-22
  • — 1992-06-18
  • — 1953-01-23
  • — 1968-07-06
  • — 1994-10-28
  • — 2006-10-24