Although each Community remained legally independent, they shared common institutions (prior to this treaty, they already shared a Parliamentary Assembly and Court of Justice) and were together known as the European Communities.
Meskipun masing-masing Komunitas independen secara hukum, ketiganya berbagi institusi umum (sebelum perjanjian ini, masing-masing komunitas sudah berbagi Majelis Parlemen dan Pengadilan) dan bersama-sama dikenal sebagai Komunitas Eropa.