What is a notice of intent in investment arbitration?
A notice of intent is a written notice from a foreign investor to a host state. It says a dispute has arisen under an investment treaty, and that arbitration will follow if the dispute is not resolved. Practitioners also call it a notice of dispute, or a trigger letter. About 90% of bilateral investment treaties (BITs) require one; it typically opens a six-month cooling-off period. See our guide to investment treaty arbitration procedure.
The notice of intent does not begin the arbitration. Proceedings start later. A party addresses a written request for arbitration to the Secretary-General under Article 36 of the ICSID Convention. The UNCITRAL Arbitration Rules use a notice of arbitration for the same purpose. Both documents come after the cooling-off period, and both go into far more detail than the notice of intent ever had to.
What must a notice of intent contain?
What the notice must contain depends on the treaty, and the newer ones ask for a lot. Article 14.D.3.2 of USMCA's Annex 14-D lists the claimant's name and address, the treaty provisions breached, the legal and factual basis, and the relief sought with the approximate damages claimed. All of it is due at least 90 days before a claim. The Energy Charter Treaty asks for far less: Article 26 says only that a dispute "shall, if possible, be settled amicably."
Older bilateral treaties are often looser still, asking for little more than written notice of the dispute. The later request needs far more. Under ICSID Institution Rule 2, the investor must add proof of consent and nationality evidence. It also needs a description of the investment and its ownership, a summary of the facts and claims, and a damages estimate.
A notice that says too little invites a jurisdictional fight later, although one that says too much can lock in positions early. Counsel tend to land in the middle.
What has to happen before a notice of intent is sent?
More happens before the letter goes out than most people expect; counsel is retained, and the treaty is checked for standing: nationality, a qualifying investment, and a clean ownership chain. Documents are gathered and early witnesses are interviewed while memories are fresh. Someone judges whether the state is likely to pay, and whether enforcement abroad will be needed. Funding gets settled too: the client pays as it goes, a funder steps in, or the firm carries the risk.
How long this takes varies enormously. About two years passed between Tanzania's cancellation of retention licences in January 2018 and Nachingwea v. Tanzania (ICSID Case No. ARB/20/38) reaching ICSID. Eiser v. Spain (ICSID Case No. ARB/13/36) moved far faster, registering on 23 December 2013, about five months after Spain's Royal Decree-Law 9/2013 abolished the fixed feed-in tariff. This groundwork happens in private; the counsel who does it usually ends up running the case. See our guide to the Fair and Equitable Treatment standard for the protections it typically pleads.
What does a notice of intent trigger, and what happens if an investor skips it?
Sending the notice starts the cooling-off period, and ignoring it can cost the whole case. The Energy Charter Treaty gives three months. USMCA's Annex 14-D requires at least 90 days and adds conditions of its own. The claimant must first take the measure to a domestic court, then either obtain a final decision or wait 30 months. The Netherlands Model BIT (2019) gives six months from the written request for consultations, and most older BITs run a similar six-month clock from the notice itself.
Murphy Exploration and Production Company International skipped that wait. It filed for arbitration against Ecuador on 3 March 2008 (ICSID Case No. ARB/08/4) without completing the six-month negotiation period that Article VI of the US-Ecuador BIT required. In its Award on Jurisdiction of 15 December 2010, the tribunal declined jurisdiction by majority, one arbitrator dissenting, because that period had not run.
Not every tribunal reads the requirement the same way. Some treat it as procedural, not jurisdictional, and would let a claim through regardless. Still, given how Murphy ended, the safer course is to serve the notice and wait out the clock. See a contemporaneous case note on the decision.
Are notices of intent public?
Usually not, even when the later filing is public. Executive Order 13990 revoked the presidential permit for the Keystone XL pipeline on 20 January 2021. TC Energy and TransCanada PipeLines did not file for arbitration against the United States (ICSID Case No. ARB/21/63) until 22 November 2021, about ten months later. The US State Department's case page publishes that request; it omits any earlier notice of intent.
The pattern holds elsewhere. The UNCITRAL Transparency Registry only requires the later notice of arbitration to be communicated to it, not the notice of intent that came before. ICSID screens a request in about three weeks and posts the basic case details on registration.
So for months the only public trace of a coming claim is the government measure that provoked it. In our experience that is the part practitioners underestimate: the letter everyone talks about is the one document nobody outside the two parties will see. See our piece on how to detect investment treaty disputes early for that window.
What this means for counsel and business development
The notice of intent is the last private step in this process. By the time anything appears on a public registry, the state already knows its opponent, and the investor has chosen counsel. A firm that wants the mandate has to watch the government measure, not wait for the notice. Monitoring tools such as DSPT Finder track new government actions and freshly served notices of dispute across more than 159 countries. That lets a team act months before the request for arbitration is filed, which is the core of business development in international arbitration.
For more on this, see why early detection of investment treaty disputes matters and ICSID caseload trends for 2026.
Frequently asked questions
What is a notice of intent in investment arbitration?
A notice of intent is a written notice from a foreign investor to a host state, saying a treaty dispute exists and arbitration will follow if it is not resolved. It is also called a notice of dispute or a trigger letter.
What is the difference between a notice of intent and a notice of arbitration?
The notice of intent warns the state and starts the waiting period. The notice of arbitration, or under the ICSID Convention a request for arbitration, is the later document that begins the case.
How long does the cooling-off period last after a notice of intent?
It depends on the treaty. Six months is the most common term in bilateral investment treaties. The Energy Charter Treaty sets three months, and USMCA's Annex 14-D requires at least 90 days' notice before a claim.
What happens if an investor files for arbitration without observing the cooling-off period?
It can lose the case before it starts. In Murphy v. Ecuador (I), the tribunal declined jurisdiction in December 2010 because the claimant had not completed the six-month period under the US-Ecuador BIT. Other tribunals treat it as procedural, not jurisdictional.
Can a business-development team see a notice of intent before the case is filed?
Rarely. Notices of intent are private letters, and registries publish only the later request or notice of arbitration. What is visible earlier is the government measure behind the notice, in gazettes, ministry announcements and local press.