Provisional application is a device in treaty law that lets parties give a treaty legal effect on a temporary basis before all conditions for entry into force—usually domestic ratification—have been met. It is codified in Article 25 of the Vienna Convention on the Law of Treaties (VCLT, 1969), which states that a treaty or part of it may be applied provisionally pending entry into force if the treaty itself so provides or the negotiating states have otherwise agreed.
States typically resort to provisional application when:
- Domestic ratification procedures are slow but the subject matter is urgent (e.g., trade liberalisation, ceasefires, commodity arrangements).
- A multilateral treaty needs a high threshold of ratifications to enter into force, and signatories want immediate operational effect.
- Interim institutional arrangements (secretariats, dispute panels) must function before the treaty formally enters into force.
Under VCLT Article 25(2), a state may terminate provisional application by notifying the other states of its intention not to become a party, unless the treaty provides otherwise. The International Law Commission adopted Guide to Provisional Application of Treaties in 2021, clarifying that provisional application produces a legally binding obligation analogous to that of a treaty in force, and that breaches can engage state responsibility.
Notable instances include the General Agreement on Tariffs and Trade (GATT 1947), which operated under a Protocol of Provisional Application for nearly half a century until the WTO came into being in 1995; the Energy Charter Treaty, provisionally applied by the Russian Federation until its withdrawal notification in 2009 (a dispute that produced the Yukos arbitral awards); and the EU–Canada Comprehensive Economic and Trade Agreement (CETA), provisionally applied from 21 September 2017 pending ratification by all EU member states.
Provisional application is distinct from signature subject to ratification, which under VCLT Article 18 only obliges a state not to defeat the object and purpose of a treaty.
Example
The EU and Canada began provisional application of CETA on 21 September 2017, allowing roughly 90% of the agreement to operate while EU member-state parliaments continued ratification.
Frequently asked questions
Yes. Under VCLT Article 25 and the ILC's 2021 Guide, provisional application creates binding obligations on participating states, and a breach can trigger state responsibility just as if the treaty were in force.
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