Partner at Armesto Dispute Resolution
In standard or complex arbitrations[1], practitioners generally invest significant effort in pre‑hearing written submissions: they craft each memorial with care and strategic precision. By contrast, they usually treat the post-hearing brief [“PHB”] – the final written submission – as an afterthought: a brief restatement of what was said at the hearing, often constrained by strict page limits. This article submits that this approach is a missed opportunity, and that the PHB should be reconceived as the primary submission.
The hearing provides the tribunal with a complete view of the case
One of the features of any legal proceeding is that the decision-maker does not have access to all the information available to the parties. Arbitrators can only work with what the parties choose to present. Before the hearing, the tribunal’s understanding of the case is filtered through written memorials (which argue the case in a light favorable to the filing party), witness statements (which offer an inevitably partial version of the facts) and expert reports (which address only what counsel instructs them to). Exhibits are also submitted but do not always paint a complete picture of the dispute.
The hearing tends to fundamentally change this. It is when witnesses and experts are tested, the evidence is examined with further context, and the tribunal engages directly with counsel. It is also the moment when the parties’ submissions are fully contrasted and the position on each disputed issue becomes clearer – narrowing the case to what truly remains in controversy.
The hearing does not give the tribunal an omniscient view – no proceeding can – but it provides something far closer to one than any prior stage. Closing submissions then bring together the documentary and oral evidence after the tribunal has heard the full story from both sides.
Oral closing submissions: a false idol
Proponents of oral closing submissions argue that they are superior to PHBs because they distill and analyze the evidence while it is fresh in the minds of the tribunal. This would supposedly prevent preliminary views from becoming entrenched before the award or dissipated owing to the passage of time. Some go further: almost every tribunal will deliberate immediately after the hearing, and a well-prepared chair will have reserved time to begin drafting the award straight away – meaning that by the time PHBs arrive, the award will largely be written and the PHBs will seldom sway the tribunal from its initial views.
These arguments overlook two practical realities.
First, oral closing submissions are rarely the product of calm and focused preparation. After an intense week (or weeks) of hearings, during which counsel have managed witnesses, conducted cross-examinations, and responded to the tribunal’s questions in real time, the team preparing an oral closing is usually exhausted. The submission that follows is hastily assembled under conditions of fatigue and time pressure. Unlike oral closing submissions, PHBs allow counsel to reflect on the full record, address the tribunal’s questions with care, and consider the evidence with the benefit of hindsight. That reflection – not the adrenaline of a closing-night rush – is what produces genuinely useful advocacy.
Second, the argument that the award will already be largely written by the time PHBs arrive is not a reason to marginalize PHBs – it is a reason to use them differently. The tribunal should indeed be working on its award even before the hearing begins; it is the only way to identify the right questions and make the most of the evidence produced at the hearing. But that process and a comprehensive PHB are not mutually exclusive. On the contrary: a well‑structured PHB can efficiently fill the gaps that remain in a draft award the tribunal has already begun to prepare.
The PHB: a missed opportunity
It is against this backdrop that the conventional treatment of the PHB appears paradoxical. The submission that follows the most informative moment in the proceedings is, precisely, the one given the least prominence. When PHBs are filed at all, they are typically constrained in scope, length and timing – drafted as short summaries rather than comprehensive restatements. The idea that they seldom sway tribunals may be a self-fulfilling prophecy: the less effort a party invests in the PHB, the less influence it will have.
The case for a comprehensive PHB
The PHB should be the submission that consolidates everything the parties wish the tribunal to address.
This is not a license to introduce new arguments or present new documentary evidence. But the hearing is a dynamic process: arguments are refined or abandoned, emphasis is placed on certain elements, oral evidence is produced and the tribunal’s questions reveal which issues require resolution. The PHB should be the vehicle for absorbing these developments and presenting a definitive articulation of each party’s case. It should be a road map for the award, identifying the live issues, the relevant evidence and the applicable legal framework. Significantly, the PHB should make clear which points have been abandoned and which remain live, sparing the tribunal from searching through prior submissions to identify what still requires determination.
Tribunals can drive this change by directing parties to file comprehensive PHBs structured around the live issues, identifying what has been maintained and what has been abandoned. Concretely:
Rather than routinely imposing low page limits, tribunals should invite parties to submit a single, consolidated brief (a sort of mémoire récapitulatif) that contains all the issues the tribunal must address, sparing it from navigating multiple prior submissions. Parties may draw from earlier submissions, but the PHB should be self‑sufficient. Because of this, pre-hearing submissions should actually be shorter than PHBs.
A few days after the hearing, once the tribunal has deliberated and identified where it requires further briefing, it should issue questions and provide a detailed structure for the PHBs, which mirrors the structure the tribunal intends to follow in its award. This guarantees that both parties address the same issues in the same order, and that the discussion does not become “two ships passing in the night”.
Parties should be required to restate their prayers for relief in clear and precise terms in the PHB, with the tribunal warning since the first procedural order that it will consider itself bound only by the relief as formulated in the PHB.
If this approach is adopted, PHBs will help the tribunal efficiently complete the remaining gaps in the award it has already begun to prepare. This will make the final submission what it should always have been: the most important one.
One counterargument is foreseeable: that arbitration already suffers from an excess of lengthy, AI-assisted written submissions, and that an expansive PHB will only add to the problem. The concern is understandable. But the answer lies not in curtailing the one submission that matters but in simplifying those that matter less.
There is a bolder proposition: why not reduce pre-hearing written submissions to a single memorial per party, subject to strict page limits, complemented by oral opening statements (and rebuttals) at the start of the hearing? The proposal may sound radical, but the overriding objective (more efficient proceedings) is not. It is precisely what users expect in this age of AI.
[1] This article does not address expedited arbitration, which typically involves no hearing or only a single round of submissions.