The 2026 International Chamber of Commerce (ICC) Arbitration Rules introduce a suite of procedural reforms designed to improve efficiency, streamline case management and reduce the time and cost of arbitration.
Whilst express witnesses or expert evidence are not explicitly referenced in the new provisions, the cumulative effect of these reforms is likely to reshape how and when expert evidence is prepared, presented and scrutinised within the ICC arbitration process.
This article will focus on a summary of the relevant changes and the impact on experts.
The Removal of the Terms of Reference
Under the new rules, the former Terms of Reference (ToR) has been replaced by a more prominent initial Case Management Conference (CMC). The CMC must be held early and serves as the point at which procedural directions are set and new claims are effectively cut off.
The implications for expert witnesses
First, there is likely to be less formal upfront definition of issues. The ToR traditionally played a useful role in crystallising the matters in dispute, often guiding the scope of expert evidence. Without it, experts may find that their instructions evolve as proceedings develop.
Second, there will be a need for earlier engagement. Counsel will need to decide before the CMC whether expert evidence is required. This may compress the timeframe for expert instruction and initial analysis.
Early determination mechanism (Article 30)
Early determination has formed part of the ICC arbitral practice since October 2017 under the Note to Parties and Arbitral Tribunals on the Conduct of the Arbitration. This mechanism allows tribunals to dispose of claims or defences that are manifestly without merit or outside their jurisdiction at an early stage.
The reforms formalise the position by integrating this mechanism into the ICC Rules.
The implications for expert witnesses
Where issues are suitable for early dismissal, tribunals may decide matters without the need for the full evidence process. For experts, this means that:
- Some engagements may never progress to full reporting stages.
- Expert involvement may become more targeted and strategic.
- Early-stage input (e.g. preliminary views) may become more valuable than full reports.
The introduction of a new Highly Expedited Arbitration Procedure (HEAP)
HEAP is a new procedure designed to deliver decisions on a significantly compressed timetable.
The implications for expert witnesses
This is likely to have a significant impact on expert witnesses - in expedited cases:
- Timelines may be too short for extensive expert reports.
- Tribunals may restrict or entirely dispense with oral expert evidence.
- There may be greater reliance on documents, joint expert reports or single joint experts.
Greater tribunal control and scrutiny
The reforms reflect a wider institutional emphasis on active case management and efficiency. Tribunals are encouraged to take a more interventionist approach to ensure proceedings remain proportionate and focused.
The implications for expert witnesses
For expert witnesses, this is likely to translate into:
- Increased scrutiny of whether expert evidence is required at all.
- Closer control over the scope of expert reports.
- Greater use of procedural tools such as:
- joint statements of issues
- concurrent expert evidence (hot tubbing)
- limits on report length or number of experts.
Experts may therefore be asked to provide more concise, issue-focused opinions with less tolerance for expansive or marginal analysis.
Conclusion
The 2026 ICC Rules reinforce a clear direction of travel: arbitration should be faster, more streamlined and tightly managed.
Although the Rules do not introduce explicit changes to expert evidence, the practical implications are clear:
- Expect earlier involvement, but potentially shorter engagements.
- Be prepared to work within tighter procedural timetables.
- Focus on clarity, concision and relevance in expert reports.
- Anticipate greater tribunal oversight of methodology and scope.
Experts who adapt to these expectations will be well placed to continue playing a pivotal role in ICC arbitrations under the new regime.
How we can help
Bond Solon provides training covering all the core skills and knowledge expert witnesses require to fulfil their role compliantly and effectively. We also offer university certified training programmes that are widely regarded as the industry gold standard by instructing parties.