On 28 August 1944, the Belgian Foreign Ministry issues a note on the draft Franco-Belgian economic agreement concerning the establishment of a limited organisation for European economic cooperation between Belgium, France, Luxembourg and the Netherlands.

Am 19. Januar 1945 verfasst der belgische Botschafter in Paris, Jules Guillaume, einen Brief für Paul-Henri Spaak, den belgischen Außenminister, in dem er die Haltung Frankreichs bezüglich der Gründung einer Zollunion zwischen Belgien, Frankreich, Luxemburg und den Niederlanden erläutert.

On 23 February 1945, Belgium and France conclude limited economic agreements on the resumption of trade, the exchange of tax information and payment facilities between their two national banks.

On 20 March 1945, Belgium, France, Luxembourg and the Netherlands sign the Economic Agreement for Mutual Consultation in Paris.