The Commercial Court Transparency Pilot: How Major is the Change?

PD51ZH may seem like a dry subject for an update, but the impact, taken together with other legal developments may have seismic consequences for the way in which hearings are prepared for and proceedings litigated.

From 1 January 2026 the Commercial Court is taking part in a pilot for two years.  As part of the pilot, the following documents should be filed by parties as Public Domain Documents:

(a) skeleton arguments;

(b) written opening submissions;

(c) written closing submissions;

(d) other written submissions provided to a judge and relied upon in the hearing;

(e) witness statements and affidavits –

(i) including those relied upon as evidence in chief at trial and those relied upon at a public hearing of an application;

(ii) not including documents appended or annexed to the witness statement or affidavit;

(f)  expert reports, including –

(i) those adduced as evidence in chief at trial and those relied upon at a public hearing of an application;

(ii) annexes and appendices to expert reports;

(g) any other document or documents critical to the understanding of the hearing ordered by the judge at the hearing to be a Public Domain Document;

(h) any documents agreed by the parties to be Public Domain Documents.

The times at which the documents should be filed, are:

1. two clear days after the start of the hearing or hearing day, in respect of written openings and skeleton arguments; and
2. for other documents within 14 days of the day on which the document was referred to in Court. The Court may impose sanctions for noncompliance.

Once filed there will be public access to those documents through public access CE file.

The Court has the power under paragraph 13 to restrict public access to all or parts of documents either on its own initiative or by application of a party or non-party named in documents under CPR Part 23. As yet, there are no published Commercial Court decisions under Paragraph 13 of PD51ZH.

However, in the last two years there have been multiple decisions of other Courts, including the Court of Appeal and Supreme Court determining applications for anonymity, access to documents on the Court file, and restricted reporting orders. These cases are likely to influence the exercise of the paragraph 13 power.

Key cases include:

• Abbassi v Newcastle upon Tyne Hospital NHS Foundation Trust [2025] UKSC 15 (39 Essex Chambers’ barristers Fiona Paterson KC, Fenella Morris KC, Alex Ruck Keene KC, Nicola Greaney KC and Ian Brownhill appeared for various parties): identifying the basis of the jurisdiction to protect the identification of third parties and witnesses during and after proceedings.
• Secretary of State for Defence v Persons Unknown [2023] EWHC 2999 (KB) and [2025] EWHC 1806 super injunctions in the context of data loss.
• PMC v Cwm Taf Morgannwg University Health Board [2025] EWCA Civ 1226 (39 Essex Chambers’ barristers Nicola Greaney KC appeared on behalf of the Attorney General and Fiona Patterson KC instructed by the Official Solicitor): the basis for the Court’s power to derogate from open justice withholding names of parties and making restricting reporting orders restriction public reporting of what was said in open court. There is no bar on the making of an anonymity order where some information relating to the individual’s identity and the claim is in the public domain. The Judgment provides detailed procedural guidance relating to the manner in which applications should be made.
• AYZ v BZA [2025] EAT 91: jigsaw identification.
• Interdigital Inc v Optis Cellular [2025] EWCA Civ 1263: correct approach to redactions for non-party’s commercially confidential information in a FRAND judgment. This judgment distinguishes between price sensitive information, which was redacted, and other information (such as whether the licenses permitted sub licensing) for which there was insufficient basis to redact.
• Bradley v CM [2026] EWHC 125 (Fam) access to expert reports from private family proceedings by a journalist who had not attended court, referring to PD51ZH and permitting access to and reporting from expert reports.
• Feldman v Gambling Commission [2025] EWHC 3117 (KB) and [2025] EWHC 474 (KB) (39 Essex Chambers David Mitchell instructed): considering a restricting reporting order (RRO) under section 4(2) of the Contempt of Court Act 1981 in relation to information disclosed in a civil claim which, if published, might prejudice an upcoming criminal trial.

Some of the commentary on PD51ZH suggests that parties will be more likely from 2026 onwards to adopt forms of ADR or to choose to arbitrate disputes, rather than fall within PD51ZH.

However, the powers are already, for the most part, in existence and the fundamental shift towards the Courts actively facilitating access to open justice has already taken place in the Courts’ case law and case management approach. Previous practices (for example regular use of 31.22 pro tem orders, or not reading passages out loud, but referring the judge to passages) have been increasingly queried in hearings.  The Judiciary website publishes all restricting reporting and anonymity orders. Active consideration of withholding orders, restricted reporting orders and confidentiality orders have become more commonplace at the pre action stage, and at the start of any case management hearing.

While arbitrations provide for increased scope to limit publicity, where there is the possibility of challenge to enforcement in the jurisdiction or challenge, there is already some case law on open justice and sections 67 and 68 Arbitration Act 1996 challenges to confidential arbitrations (for example Manchester City Football Club Ltd v Football Association Premier League Limited [2021] EWCA Civ 1110) Arbitrations may still give greater scope to limit publicity than litigation and this is likely to influence parties’ choices when drafting agreements.

What PD51ZH arguably does is:

1. To make it simpler and less costly for non parties to access the information on the Court file than where an application would be made under CPR 5.4C and Cape Intermediate Holdings Ltd v Dring [2019] UKSC 38.
2. Hail a new technological capability of the Court’s filing portal CE file, itself, which is not necessarily limited to the Commercial Court. It is now straightforward to register for public access to CE file and, similar to Courts in other jurisdictions (for example the Federal Courts of Canada) to have access to documents on the case file directly.
3. Make it more difficult for parties to limit the amount of scrapable data accessible about them, and limit lawyers’ ability to prevent scraping of their work output. There are already services which scrape publicly accessible data from CE file to provide records of case names, solicitors acting, hearing and orders. However, the new capability of the CE file site developed for the portal creates a significantly larger volume of publicly accessible documents which can be scraped and reproduced elsewhere (including through Gen AI) than previously.
4. Potentially alter the time points for parties to consider what costs to include on a costs budget for addressing either an application for a paragraph 13 order, or to provide for documents in a format that parties are content to be publicly accessible through public access to CE file.
5. Increase the prospects of third parties applying, post hand down of judgment, for paragraph 13 orders or for amendment of the handed down judgment to remove information relating to them or their confidential information which the parties had not sought sufficiently to protect (as occurred in the Interdigital case).

There is also a new Portal for the UK Supreme Court Website under the Supreme Court Rules 2024 and the parties’ cases are now routinely published on the Supreme Court website in their entirety.

PD51ZH is part of an emerging picture underlining the Courts’ increased focus on open justice and the technical reorganisation of Court office files, across all jurisdictions to increase web searchability by the public in common with many large Court system registries worldwide. There are multiple aspects to the Courts’ rationale for doing so, including combatting misinformation about cases online and aiming to reduce the potential for time consuming satellite litigation about access to the Court file. The increased publicity also enables students and future aspiring lawyers to see more of what the being a barrister involves in “real life,” and have access to the type of material previously only accessible through doing mini-pupillages and vacation schemes with law firms.

For parties engaged in commercially sensitive litigation, these dry procedural changes can be  significant. Their skeleton arguments may well no longer be read wholly or mainly by lawyers and judges, but will be more readily accessible to journalists, future investors, customers, their competitors and the public.

Witnesses too, although protected by judicial proceedings immunity in relation to potential legal claims arising from their evidence, may wish to know that their words may well be accessible through CE file for a significant period of time. This could be long after their statement has been produced for the particular litigation.