Ratification is the process by which a principal confirms an act of its agent, or by which a state declares its consent to be bound to a treaty. It is a formal approval or sanction of an agreement, treaty, or legally binding act that would not otherwise be binding in the absence of such approval. The term applies to private contract law, international treaties, and constitutions in federal states such as the United States and Canada.

In international law, the institution of ratification grants states the necessary time-frame to seek the required approval for the treaty on the domestic level and to enact the necessary legislation to give domestic effect to that treaty. In the context of contract law, the need for ratification often arises in two ways: if the agent attempts to bind the principal despite lacking the authority to do so, or if the principal authorizes the agent to make an agreement but reserves the right to approve it.

The difference between signing and ratification is that signing is an agreement between national delegations, while ratification is the approval of the agreement by the state. Once a treaty has been signed, each state will deal with it according to its own national procedures. In the Netherlands, parliamentary approval is required. After approval has been granted under a state’s own internal procedures, it will notify the other parties that they consent to be bound by the treaty. This is called ratification, and the treaty is now officially binding on the state.