Treaties to which a Member State of the United Nations becomes a party must be registered with the UN, under Article 102 of the UN Charter, in all their languages and with all their ancillary documents. The intention of this requirement is to discourage secret treaties. In theory, no Member State may invoke a treaty before the International Court of Justice or any other organ of the UN unless the treaty has been registered. Regulations to give effect to Article 102 were adopted by the General Assembly on 14 December 1946, and have been modified several times since.

Treaties are subsequently published by the UN, both on the internet and on paper, in the United Nations Treaty Series (see Links page).

FCO Treaty Section is responsible for the registration of:

(a) all bilateral treaties concluded by the UK which have been published in the UK Treaty Series and have therefore entered into force.

(b) multilateral treaties of which the UK is depositary, when they have entered into force, whether or not the UK is a party.

Other multilateral treaties are registered by the organisation or foreign State with which they are deposited.