Ercüment Erdem Att. Melissa Balıkci Sezen

IBA Rules on Taking of Evidence in International Arbitration 2020

March 2021


On 15 February 2021, the International Bar Association (“IBA”) released a revised version of the Rules on Taking of Evidence in International Arbitration (“IBA Rules 2020” or “Rules”).

The IBA Rules on Taking of Evidence in International Arbitration are a set of rules adopted in commercial and investment arbitrations. These rules deal with the taking of evidence and aim to provide a balance between parties with different legal backgrounds. As stated in the Preamble of the Rules, these Rules are intended to provide an efficient, economical and fair process for the taking of evidence in international arbitrations and are designed to supplement the legal provisions and the institutional, ad hoc or other rules that apply to the conduct of the arbitration.                                                                                                                                                                            

The first set of rules were published by the IBA in 1999, which were revised in 2010. In 2019, a task force was established to study whether any revisions were required[1], and on 17 December 2020, the IBA Rules 2020 were adopted by a resolution of the IBA Council.

General Information

The IBA Rules apply where parties and arbitral tribunals adopt them, in whole or in part, to govern arbitration proceedings. The parties are free to vary the Rules or use them as guidelines.

According to article 1.2 of the IBA Rules, where parties have agreed to apply the IBA Rules of Evidence, in whole or in part, they shall be deemed to have agreed, in the absence of a contrary indication, to the version as current on the date of such agreement. In line with this, the IBA Rules 2020 will apply to arbitration agreements concluded after 17 December 2020 or, if the parties agree, may be applicable to arbitrations commenced after the same date.

In its first article, the IBA Rules set out the scope of application of the Rules. This is followed by article 2 which deals with consultation on evidentiary issues. Article 3 deals with documents and document production requests.[2] Article 4 sets out rules regarding witnesses of fact. Articles 5 and 6 deal with party-appointed experts and tribunal-appointed experts, respectively. This is followed by article 7, entitled “Inspection” and article 8 “Evidentiary Hearing.” Lastly, article 9 outlines the rules on admissibility and assessment of evidence.

The IBA Rules are also supplemented by detailed commentary which provides useful additional information for practitioners.

Main Changes

The changes made to the Rules are limited and aim to ensure greater clarity. Important changes are listed below:

  • Cybersecurity and Data Protection

As mentioned above, article 2 of the Rules deals with evidentiary issues. Article 2.2 lists certain issues that should be addressed during the consultation on evidentiary issues. An item of issues of cybersecurity and data protection has been introduced as article 2.2(e). Cybersecurity threats are more common and are now a serious concern. Additionally, with the increased use of technology there may be data protection issues arising out of for example during remote hearings and sharing documents during the proceedings. If such issues are dealt with at an early stage of the proceedings, this will clearly prevent exposure of data.

  • Remote Hearings

As a result of the Covid-19 pandemic, many hearings have been held online. In line with this, the IBA Rules 2020 now include a definition of a remote hearing which reads as follows: “A hearing conducted, for the entire hearing or parts thereof, or only with respect to certain participants, using teleconference, videoconference or other communication technology by which persons in more than one location simultaneously participate.

Article 8 has also been amended and now expressly refers to Remote Hearings and states that even parts of a hearing may be held remotely. According to article 8.2, at the request of a Party or on its own motion, the arbitral tribunal may, after consultation with the Parties, order that the evidentiary hearing be conducted as a Remote Hearing. In that event, the Rules state that, the arbitral tribunal should consult with the Parties with a view to establishing a Remote Hearing protocol to conduct the Remote Hearing efficiently, fairly and, to the extent possible, without unintended interruptions.

The said article also addresses certain items that the protocol may address, such as the technology to be used, testing of the technology, or training in the use of the technology, the start and end times considering, in particular, the time zones in which the participants will be located. The article also suggests that measures to ensure that witnesses giving oral testimony are not improperly influenced or distracted should be considered.

  • Tribunal powers

A new provision to article 9 has been added which clearly empowers the arbitral tribunal with the authority to exclude evidence obtained illegally, either at the request of a party or on its own motion.

In addition, article 8.5 states that parties may agree, or the arbitral tribunal may order, that the witness statement or expert report shall serve as that witness’s direct testimony. A new sentence has been included that in this event the arbitral tribunal may, nevertheless, permit further oral direct testimony. This clarifies the arbitral tribunal’s power to order direct testimony even if the other party has waived its right to cross-examine that witness.

In addition to the above, a new subparagraph has been included in article 4.6 (Witnesses of Fact) which deals with the submission of witness statements. Previously, revised or additional witness statements, including statements from persons not previously named as witnesses, were allowed, so long as any such revisions or additions responded only to matters contained in another party’s witness statements, expert reports, or other submissions that have not been previously presented in the arbitration. Now, it is clear that a second round of witness statements are allowed in case new factual developments that could not have been addressed in a previous witness statement exist.

A similar amendment has been made to article 5.3 (Party-Appointed Experts).


The revisions made to the Rules are not fundamental changes but are welcome clarifications. Considering the Covid-19 pandemic, many institutions have made amendments to their rules, in order to better reflect current practices, such as conducting remote hearings, and the IBA has done the same in this respect. The IBA Rules 2020 aim at increasing the efficiency of arbitrations and reducing costs, to the extent possible.


[2] Please see Babur, Ezgi: “Document Production Requests Pursuant to IBA Rules on The Taking of Evidence in International Arbitration”, Erdem & Erdem Newsletter, January, 2016, and Babur, Ezgi: “Document Production Requests Pursuant to the IBA Rules on The Taking of Evidence in International Arbitration”, Erdem & Erdem Newsletter, May, 2016, and