Evidence and disclosure - Electronic disclosure

Learning Outcomes

This article explains the principles and procedures surrounding electronic disclosure within civil litigation in England and Wales. After reading this article, you should understand the scope of electronic disclosure, the duties imposed on parties by the Civil Procedure Rules (CPR), particularly Practice Direction 31B, the concepts of proportionality and reasonable search in the context of electronically stored information (ESI), and the management of privilege in electronic documents. This knowledge will assist you in applying the relevant rules to SQE1 assessment scenarios involving the disclosure of digital evidence.

SQE1 Syllabus

For SQE1, you are required to understand the processes involved in the disclosure of documents, specifically including electronically stored information (ESI), with a focus on the following syllabus points:

• the definition and scope of electronic disclosure under CPR Part 31 and Practice Direction 31B
• the duties relating to the identification and preservation of electronically stored information (ESI)
• the concepts of proportionality and reasonable search in the context of electronic documents
• the role and use of the Disclosure Report and Electronic Documents Questionnaire (EDQ)
• the management of privilege and redaction in electronic disclosure
• the impact of technology on the disclosure process.
• the distinction between disclosure and inspection, and how inspection is exercised under CPR 31.3 and 31.15
• how specific, pre-action, and non-party disclosure applications can be used to address deficiencies in e-disclosure
• the continuing nature of the disclosure duty and the consequences of false or inadequate disclosure

Test Your Knowledge

Attempt these questions before reading this article. If you find some difficult or cannot remember the answers, remember to look more closely at that area during your revision.

1. Under Practice Direction 31B, what is the primary factor governing the extent of the search required for electronically stored information (ESI)?
   1. The financial resources of the disclosing party.
   2. The agreement reached between the parties' IT departments.
   3. The principle of proportionality.
   4. The volume of data held by the receiving party.
2. Which of the following best describes electronically stored information (ESI) for the purposes of disclosure?
   1. Only emails and word-processed documents stored on a company's central server.
   2. Any information recorded electronically, including metadata, emails, databases, and social media posts.
   3. Documents scanned into PDF format.
   4. Data stored exclusively on portable devices like USB sticks.
3. What is the main purpose of an Electronic Documents Questionnaire (EDQ)?
   1. To provide the court with a final list of all disclosable ESI.
   2. To facilitate discussion and agreement between parties on the scope and methodology of electronic disclosure.
   3. To act as a substitute for standard disclosure lists in cases involving ESI.
   4. To apply for specific disclosure of electronic documents from the opposing party.

Introduction

The digital age has transformed the nature of evidence in legal disputes. Electronically Stored Information (ESI) often forms the bulk of relevant documentation in modern litigation. Electronic disclosure, or e-disclosure, is the process governed by the Civil Procedure Rules (CPR) for managing this digital evidence. It involves identifying, preserving, collecting, processing, reviewing, and producing ESI relevant to the issues in a case. Understanding the specific rules and practical considerations surrounding e-disclosure is essential for effective case management and compliance with court requirements.

This article focuses on the key principles governing electronic disclosure in England and Wales, particularly as outlined in CPR Part 31 and Practice Direction (PD) 31B. While CPR Part 31 applies to most claims except small claims, note that in the Business and Property Courts a separate disclosure regime operates under PD 51U (the disclosure pilot), which places emphasis on initial and extended disclosure models. For the majority of civil claims outside that pilot, the framework in CPR 31 and PD 31B remains the core reference point.

Key Term: Electronic Disclosure
The process by which parties involved in litigation identify, preserve, collect, process, review, and exchange electronically stored information (ESI) relevant to the case, in accordance with court rules.

Key Term: Electronically Stored Information (ESI)
Information that is stored electronically, regardless of the medium or format. This includes emails, databases, word-processed documents, spreadsheets, presentations, social media content, voicemail, instant messages, video files, device logs and associated metadata.

Key Term: Control
For disclosure purposes, a document is within a party’s control if it is or was in their physical possession, or they have (or had) a right to possession, inspection, or to take copies (CPR 31.8).

The Legal Framework for Electronic Disclosure

CPR Part 31 sets out the general rules for disclosure and inspection of documents in civil proceedings. PD 31A provides guidance on standard disclosure and lists, while PD 31B supplements Part 31 by providing specific guidance on the disclosure of electronic documents.

PD 31B emphasises that parties should cooperate and discuss issues relating to electronic disclosure at an early stage. This is central to ensuring e-disclosure is conducted efficiently and at proportionate cost. The Practice Direction sets out general principles, including that:

• electronic documents should be managed efficiently to minimise costs
• appropriate technology should be used to perform document management activities effectively
• disclosure should be conducted to further the overriding objective
• electronic documents should be made available for inspection in a form that allows the receiving party substantially the same ability to access, search, review and display the documents as the disclosing party
• disclosure of electronically stored documents of no relevance should be avoided as it imposes unnecessary burden

Early discussions should cover sources of ESI, retention policies, the scope of reasonable searches (for example, custodians, date ranges, file types), and tools or techniques to reduce costs (agreed keywords, software tools, deduplication, email threading, sampling, staged disclosure). The parties should also agree formats for production and inspection, and how to handle privileged and confidential material, including mechanisms for inadvertent production.

Key obligations include:

• Duty of Preservation: Parties must take reasonable steps to preserve ESI which may be relevant, including suspending routine data deletion, backup tape recycling, or auto-purge settings for email and instant messaging platforms. A litigation hold should be implemented promptly to prevent loss.
• Cooperation: Parties are expected to cooperate in relation to electronic disclosure to ensure the process is efficient and cost-effective, including sharing information via the EDQ.
• Disclosure Report: In multi-track claims (except personal injury), parties must file and serve a Disclosure Report (Form N263) detailing the documents (including ESI) that exist or may exist, their location and storage, and an estimate of the broad range of costs of giving standard disclosure.
• Electronic Documents Questionnaire (EDQ): While not mandatory, the EDQ (Form N264) is a helpful tool to facilitate discussions between parties about the scope and methodology for electronic disclosure. In substantial or complex cases, courts expect parties to exchange the EDQ before the first case management conference (CMC).

Key Term: Disclosure Report
A report verified by a statement of truth, filed at least 14 days before the first CMC in non-personal injury multi-track cases, that describes relevant documents (including ESI), where they are held, how electronic documents are stored, and gives a cost estimate for disclosure.

Key Term: Electronic Documents Questionnaire (EDQ)
A questionnaire exchanged between parties to capture information about the nature, scope and storage of ESI, sources to be searched, search methods, formats for production, and measures for privilege and inadvertent disclosure.

Worked Example 1.1

A claimant has issued a multi-track claim against a technology company. Both parties exchange an EDQ. The claimant identifies ESI located on cloud-based collaborative platforms (e.g., Slack and Microsoft Teams), personal smartphones of key custodians (BYOD), and legacy backup tapes. The defendant proposes limiting searches to company email servers and shared drives, excluding instant messaging and BYOD devices due to cost.

Answer:
The parties should revisit PD 31B para 9 and agree a proportionate scope. Instant messaging and collaborative platforms often contain relevant contemporaneous communications, so excluding them entirely risks inadequate disclosure. A reasonable approach might limit searches to relevant custodians and targeted date ranges, use agreed keywords and channel selection within Slack/Teams, and sample BYOD devices for key custodians with appropriate privacy safeguards. Legacy backup tapes may be excluded if retrieval is unduly burdensome and unlikely to yield unique, probative documents beyond active data sources, provided this limitation is explained in the disclosure statement.

The E-Disclosure Process

The management of ESI typically follows a workflow designed to handle the volume and complexity of digital data. PD 31B encourages parties to agree the steps and tools used to keep costs proportionate and maintain data integrity.

Identification and Preservation

The first step is to identify potential sources of relevant ESI (e.g., servers, laptops, mobile devices, cloud storage, enterprise applications, instant messaging platforms, shared drives, third-party repositories, backup tapes) and the types of data they hold. This often involves creating a data map of systems, custodians, and retention policies. Once identified, this data must be preserved to prevent loss or alteration. This typically involves issuing a 'litigation hold' notice within an organisation, suspending routine deletion (including auto-deletion on messaging platforms), preserving device images for key custodians if proportionate, and instructing IT to prevent changes to relevant custodians’ data.

Key Term: Litigation Hold
An internal notice instructing custodians and IT functions to preserve potentially relevant documents and ESI, suspending routine deletion or alteration until the litigation risk ends.

Preservation must also consider third-party service providers and data outside the organisation’s direct control. Parties should act promptly and document preservation steps to demonstrate compliance.

Collection and Processing

ESI is collected using methods that maintain data integrity, including preserving metadata. Forensic collection techniques may be appropriate where data authenticity is likely to be contentious, or for mobile devices. Chain of custody records and cryptographic hash values are commonly used to maintain evidential integrity.

Key Term: Metadata
Data about data, providing context for electronic documents, such as creation date, author, modification history, email headers, geolocation, device identifiers and file hash values. Metadata can be essential evidence.

Collected data is then processed to prepare it for review. This may involve filtering irrelevant data, removing duplicate files (deduplication), email threading, converting files to a common format, and indexing the data for searching. Agreed deduplication and threading parameters reduce review volume while maintaining completeness. Parties should agree production formats (native, text plus images like PDF/TIFF, with load files and metadata fields) to ensure the receiving party has equivalent access for search and analysis.

Review and Production

Legal teams review the processed data to determine its relevance to the issues in the dispute and to identify any documents subject to legal privilege or confidentiality. Review strategies should be documented and justified if challenged. Quality control (QC), sampling, and defensible protocols help show the search was reasonable.

Technology-assisted review (TAR), including predictive coding, is often employed to manage large datasets efficiently. Courts in England and Wales have accepted the use of predictive coding in appropriate cases, particularly where it can deliver more efficient and cost-effective disclosure consistent with the overriding objective.

Key Term: Predictive Coding
A form of technology-assisted review (TAR) where software uses algorithms, trained by human reviewers coding a sample set of documents, to predict the relevance of a larger dataset. It can significantly reduce review volumes and costs when used with appropriate validation and QC.

Relevant, non-privileged ESI is then produced to the opposing party in an agreed format, often electronically. Parties should include a privilege log describing withheld documents by category (without disclosing privileged content) and apply redactions to irrelevant or sensitive material where appropriate.

Key Term: Privilege Log
A description, usually categorical, of withheld documents claimed to be privileged or confidential, providing enough information to support the claim without revealing privileged content.

Key Term: Redaction
The removal or masking of parts of a document before production to protect privileged, irrelevant, or confidential information while disclosing relevant portions.

Production should follow any agreement on metadata fields and load files, with encryption or secure file transfer. If inspection is requested under CPR 31.3 and 31.15, copies must be provided or inspection permitted within seven days, unless an exception applies (privilege, loss of control, or disproportionate burden justifiably claimed).

Worked Example 1.2

A construction dispute involves millions of emails and drawings stored across multiple systems. The parties agree to use TAR with predictive coding, seed sets drawn from liability issues only, and validate the model by sampling. The claimant insists on receiving native CAD files plus a limited set of metadata fields; the defendant prefers PDFs.

Answer:
The parties should agree a production protocol reflecting PD 31B’s principle that inspection should allow the receiving party substantially equivalent access. Where functionality or analysis requires native format (e.g., CAD layers), native production is appropriate for those files, with PDFs or images used for other documents. Metadata fields (e.g., author, dates, file path, hash) should be agreed in a load file to preserve context. TAR can be used to prioritise review, but the parties should document training, validation metrics, and QC sampling to demonstrate a defensible approach.

Proportionality and Reasonable Searches

The potential volume of ESI means that the scope of electronic disclosure must be managed proportionately.

Key Term: Proportionality
A core CPR principle requiring that the costs and effort involved in litigation steps, including disclosure, should be proportionate to the value, complexity, importance of the case, and the likely benefit of the steps.

PD 31B explicitly requires parties and the court to consider proportionality when determining the scope of electronic disclosure. Factors include:

• the number of documents involved
• the nature and complexity of the proceedings
• the ease and expense of retrieval of particular documents (including from backup systems or personal devices)
• the significance of any ESI likely to be located
• the financial position of the parties and the need to keep costs to a sensible level

Reasonable Searches

CPR 31.7 requires parties giving standard disclosure to make a reasonable search for relevant documents, including ESI falling within CPR 31.6(b) (adverse documents) and (c) (documents supporting another party's case). Reasonableness is assessed in light of proportionality. A reasonable search will be tailored to the issues and data context, and may include:

• scoping searches by custodians, systems, and date ranges
• agreed keyword lists, mindful that keyword-only approaches may be inadequate without testing and refinement
• use of software tools (de-duplication, threading, concept clustering)
• sampling to validate search efficacy
• excluding sources where retrieval would be unduly burdensome with limited likely benefit (e.g., legacy backup tapes), provided exclusions are explained in the disclosure statement

Parties should avoid unilateral search strategies. Cooperation in agreeing search terms and methodologies is required by PD 31B, and courts have criticised keyword lists that are untested or unsuitable for the case. Reasonable limits should be recorded in Form N265’s disclosure statement, explaining categories not searched and why.

Key Term: Reasonable Search
A search for disclosable documents (including ESI) that is reasonable in the circumstances, considering factors like the number of documents, complexity, cost of retrieval, and significance, as required by CPR 31.7.

Worked Example 1.3

A claimant company (C Ltd) sues a defendant company (D Ltd) for breach of contract concerning a software development project. C Ltd identifies that relevant emails might exist on the personal laptops of 50 former employees who worked on the project over five years ago. D Ltd requests disclosure of these emails. C Ltd estimates the cost of forensically collecting and reviewing data from these laptops would be £150,000. The total value of the claim is £75,000. How should C Ltd respond?

Answer:
C Ltd should argue that the requested search is disproportionate under PD 31B. The estimated cost (£150,000) significantly exceeds the claim value (£75,000). C Ltd should state in its Disclosure Report (if applicable) or correspondence that it has not searched these laptops on the grounds of disproportionality, explaining the estimated cost and the potential limited significance of any documents likely found on such old devices belonging to former employees. The parties should discuss alternative, more proportionate search methods, perhaps focusing on key custodians or specific keywords on central servers.

Worked Example 1.4

A retailer’s emails from 2017–2019 are archived to tape. The opponent demands restoration and review of the tapes, alleging potential adverse documents. The retailer demonstrates that all relevant active mailboxes and shared drives have been searched using agreed terms and TAR, and that tape restoration would cost £80,000 with no reason to think unique relevant documents exist.

Answer:
It is reasonable to resist tape restoration on proportionality grounds unless there is evidence that unique, significant adverse documents are likely only on tapes. PD 31B contemplates limiting burdensome sources. The retailer should record the limitation in its disclosure statement, explain the alternative searches conducted, and offer sampling (e.g., restoration of a small number of tapes for key periods/custodians) if that would resolve concerns proportionately.

Privilege and E-Disclosure

Protecting legally privileged material is a critical aspect of e-disclosure. The main types of privilege are legal advice privilege and litigation privilege. Without prejudice privilege also applies to genuine settlement communications. Privileged documents must be disclosed by category in the list (with inspection withheld) but not produced for inspection.

Privilege management in e-disclosure requires processes to identify and segregate privileged documents, often using search terms (e.g., law firm names, “legal advice”, “counsel”), custodian filters, and manual QC. Redactions can protect privileged portions in otherwise disclosable documents. A privilege log should be maintained to support claims without revealing content. Common interest privilege may apply in some circumstances, and public interest immunity can justify non-disclosure of sensitive state or public interest material.

Inadvertent disclosure can occur despite careful review, particularly in large datasets or when TAR is used. If privileged material is accidentally produced, the receiving party must consider CPR 31.20 and the “obvious mistake” principle; they should not use the material without the court’s permission where an obvious mistake has occurred. Cooperation and agreed clawback mechanisms reduce satellite disputes.

Key Term: Clawback Agreement
An agreement between parties in litigation that allows for the retrieval of inadvertently disclosed privileged documents without waiving privilege, typically setting out notice and return procedures and non-use undertakings.

Worked Example 1.5

During electronic disclosure in a commercial dispute, a junior lawyer at Firm A reviews a batch of emails produced by the opposing party, Firm B. The lawyer discovers an email clearly marked "Legally Privileged & Confidential - Advice from Counsel" attached to an internal message discussing litigation strategy. What should the junior lawyer do?

Answer:
The lawyer should immediately stop reading the document and any related attachments, isolate the document(s), and inform their supervising solicitor. The supervising solicitor should then notify Firm B that potentially privileged material appears to have been inadvertently disclosed. Continuing to read or making use of inadvertently disclosed privileged material can lead to serious professional conduct issues and potential court sanctions. The parties may have a 'clawback agreement' in place to manage such situations.

Privilege issues also interact with ethical duties. Solicitors owe duties of confidentiality to clients and must not misuse inadvertently disclosed privileged material. A disclosure list may include privileged entries by category, but content is not revealed. If privilege is waived (by the client), inspection may be permitted. Privilege can be lost if a document’s content is deployed openly (for example, referred to substantively in a statement of case or in open court), and care must be taken not to reference privileged material in a way that effects waiver.

Technology in E-Disclosure

Technological tools are indispensable for managing the scale and complexity of ESI. PD 31B encourages the use of technology consistent with the overriding objective. Key technologies include:

• Processing platforms to ingest, filter, de-duplicate, thread emails, and index ESI
• Review platforms providing search, coding, QC sampling, and redaction tools
• Analytics such as concept clustering, near-duplicate identification, and TAR
• Export tools to produce agreed formats (native, image plus text, load files with metadata fields)
• Secure transfer tools and repositories, including neutral electronic repositories where agreed

Parties should discuss and agree the use of technology at an early stage, including:

• formats for production and inspection (native vs image; required metadata fields)
• time-zone normalisation and handling of family relationships (emails and attachments)
• deduplication scope (global vs custodian-level)
• email threading use to reduce duplicate content review
• safeguards for confidential material (confidentiality rings, protective orders)
• QC and validation measures where TAR is deployed

Key Term: Technology-Assisted Review (TAR)
The application of machine learning and other analytics to prioritise and identify relevant documents more efficiently than manual review alone. TAR encompasses predictive coding, clustering, and other tools used with human oversight, validation, and QC.

Exam Warning

Be aware that simply using keywords may not constitute a 'reasonable search'. The appropriateness of keywords, search strategies, and the use of technology should be considered in light of the specific issues and data context of the case. Parties should be prepared to justify their search methodology to the court.

Summary

Electronic disclosure is governed by CPR Part 31 and PD 31B. Key duties include preservation of relevant ESI and cooperation between parties. The process involves identifying, preserving, collecting, processing, reviewing, and producing ESI. Proportionality is critical, balancing the scope of disclosure against the case's specifics. Parties must conduct reasonable searches for ESI and record any limitations in disclosure statements. Legal privilege must be carefully managed, using redaction, privilege logs, and clawback agreements. Technology plays a key role in efficiently handling large volumes of ESI, but its use must be reasonable, explained, and often agreed upon. In multi-track cases, the Disclosure Report and EDQ are central to scoping and managing e-disclosure. Where disclosure is inadequate, specific disclosure and non-party disclosure applications can be used to ensure compliance.

Key Point Checklist

This article has covered the following key knowledge points:

• Electronic disclosure involves managing Electronically Stored Information (ESI) under CPR Part 31 and PD 31B.
• Parties have duties to preserve relevant ESI and cooperate on disclosure processes, including early discussions and use of the EDQ.
• The concept of proportionality is central in determining the scope of e-disclosure searches and production.
• Reasonable searches for ESI must be conducted, considering factors like cost, volume, significance, and ease of retrieval; exclusions must be justified in disclosure statements.
• Metadata associated with electronic documents can be important evidence and must be preserved.
• Legal privilege applies to ESI; careful review, privilege logs, redaction, and clawback agreements are needed to manage privileged information and inadvertent disclosure.
• Technology, including TAR and predictive coding, is often used to manage the volume and complexity of ESI, but its use must be justified, validated, and proportionate.
• The Disclosure Report (Form N263) and the Electronic Documents Questionnaire (EDQ, Form N264) help facilitate agreement on e-disclosure methods and scoping.
• Inspection rights under CPR 31.3 and 31.15 require timely access or copies unless privilege, loss of control, or disproportionality applies.
• Where disclosure appears inadequate, parties may seek orders for specific disclosure or non-party disclosure; proportionality guides the court’s approach.

Key Terms and Concepts

• Electronic Disclosure
• Electronically Stored Information (ESI)
• Control
• Litigation Hold
• Metadata
• Proportionality
• Reasonable Search
• Disclosure Report
• Electronic Documents Questionnaire (EDQ)
• Privilege Log
• Redaction
• Technology-Assisted Review (TAR)
• Predictive Coding
• Clawback Agreement