The decision to establish an economic union was taken by OECS Heads of Government at the 34th meeting of the Authority held in Dominica in July 2001.

At the 35th meeting of the Authority in Anguilla in January 2002, the main elements of an economic union implementation project were endorsed.

The project was expected to be implemented over a two-year period with seven of the nine OECS member states (i.e. Antigua and Barbuda, Dominica, Grenada, Montserrat, St. Kitts and Nevis, St. Lucia and St. Vincent and the Grenadines) participating in the economic union initiative.

The remaining two member states, Anguilla and the British Virgin Islands, would not have participated immediately, but would have requested time to consider the issue further.

[10] The Authority requested changes to allow a role for national parliamentary representatives (both government and opposition) of the Member States in the form of a regional Assembly of Parliamentarians.

It was agreed in the Declaration, that implementation of the Treaty would occur only after a year of public consultation, through a mass national and regional education programme with strong political leadership and direction.

[24] This was achieved in 2013 at the Twenty-Fourth Inter-Sessional Meeting of the Conference of Heads of Government of CARICOM held in Port-au-Prince, Haiti, from 18–19 February 2013.

[26] The Economic Union Treaty's provisions are now expected to establish a Single Financial and Economic Space within which goods, people and capital move freely; harmonize monetary and fiscal policies Member States are expected continue to adopt a common approach to trade, health, education and environment, as well as to the development of such critical sectors as agriculture, tourism and energy.

[27] The free movement of OECS nationals within the subregion is expected to commence in August 2011 after a commitment towards that goal by the Heads of Government at their meeting in May 2011.

Three others, Anguilla, the British Virgin Islands, and Montserrat remain overseas territories of the UK while Martinique and Guadeloupe are French departments and regions of France.

Eight of the eleven members are constitutional monarchies with King Charles III as their current monarch (Dominica is a republic with a President).

[35][36] In 2019 the OECS Authority agreed to approve the transition of Saint-Martin from observer status to associate membership by the end of December 2019.

The first was the United States Virgin Islands, which applied for associate membership in February 1990[46] and requested that US Federal Government allow the territory to participate as such.

In addition to the support from the Antillean parliament, Saba also required a dispensation from the government of the Kingdom of the Netherlands to become an associate member of the OECS.

[48] Saba's bid for membership was reportedly supported by St. Kitts and Nevis and discussed at the 34th meeting of OECS leaders in Dominica in July.

[52] On 13 August 2008 the leaders of Trinidad & Tobago, Grenada, St. Lucia, and St. Vincent & the Grenadines announced their intention to pursue a sub-regional political union within CARICOM.

The functions of the Organisation are set out in the Treaty of Basseterre and are coordinated by the Secretariat under the direction and management of the Director General.

It is the purpose of the Organisation to assist its Members to respond to these multi-faceted challenges by identifying scope for joint or coordinated action towards the economic and social advancement of their countries.

The restructuring of the Secretariat was informed by considerations of cost effectiveness in the context of the need to respond to the increasing challenges placed on it, taking into account the limited fiscal capacities of its members.

The Secretariat consists of four main Divisions responsible for: External Relations, Functional Cooperation, Corporate Services and Economic Affairs.

The current Director General of the OECS is Dr. Didacus Jules (Registrar and Chief Executive Officer of the Barbados-based Caribbean Examinations Council), who took his new position on 1 of May 2014.

Of all OECS member-states, only the British Virgin Islands, Guadeloupe and Martinique do not use the East Caribbean dollar as their de facto native currency.

Cases appealed from the stage of ECSC Supreme Court will then be referred to the jurisdiction of the Judicial Committee of the Privy Council.