What evidence should I preserve when a commercial dispute starts?

The instinct to tidy up a file once a dispute starts is understandable. It is also dangerous.

Once litigation is reasonably anticipated, a duty to preserve relevant documents arises. That duty is not limited to documents which support your case. It extends to documents which are adverse to it.

Deleting a document because it looks unhelpful does not make the dispute easier to manage. It creates a separate and potentially serious problem: a court may draw adverse inferences from unexplained gaps in disclosure, and deliberate destruction of relevant material can lead to costs consequences and other case-management sanctions. Contempt requires an applicable legal basis, such as breach of a court order or a knowingly false disclosure statement verified by a statement of truth; it is not the automatic consequence of every deletion.

The practical approach is to take reasonable steps to preserve potentially relevant material — including material that may be adverse — once a dispute is in prospect. That means suspending relevant deletion routines, identifying the people, systems and time periods likely to hold relevant material, and preserving material where you are uncertain whether it is relevant pending advice. The aim is a proportionate preservation plan, not indefinitely retaining every record in the organisation.

The definition under CPR Part 31 is deliberately broad. A document is anything in which information of any description is recorded. That is not limited to formal written records.

In practice it includes: emails and email attachments; WhatsApp messages, texts and other messaging app conversations; Microsoft Teams and Slack messages; voice notes and voicemails; photographs and videos; spreadsheets and databases; CCTV footage; meeting notes and board minutes; draft documents, even where they were never finalised or sent; and metadata — the data about data, such as when a file was created, last modified or accessed, and by whom.

It also includes deleted material which has not been permanently overwritten. Deletion from a device or inbox does not necessarily mean the information has gone. Recovery may be possible from available device data, backups or another participant’s copy, but it is not guaranteed. Some deleted material cannot be recovered. Recovery depends on the device, backup settings and how much time has passed.

Practice Direction 31B, which governs electronic documents, and Practice Direction 57AD, which applies in the Business and Property Courts, both reflect the reality that the majority of relevant material in modern commercial disputes is electronic. The scope of what must be considered is wide.

Before thinking about phones and messaging apps, secure the core paper trail.

That will typically include: the contract and any amendments, variations or side letters; pre-contractual documents such as heads of terms, term sheets or letters of intent; formal notices, termination letters or demands; invoices, payment records and bank statements; delivery records, acceptance documents and sign-off sheets; board minutes, management accounts and internal reports relevant to the subject matter; and correspondence with third parties such as brokers, agents, valuers or advisers.

These documents form the skeleton of the chronology. Without them, it is difficult to understand what the parties agreed, what happened and where the dispute actually lies.

This is the area where preservation most often goes wrong.

Commercial conversations increasingly happen on personal devices and personal messaging accounts. A director negotiating a contract variation over WhatsApp on their personal phone, a sales manager discussing delivery problems in a group chat, a finance director sending a voice note about a disputed payment — all of these may be relevant documents for the purposes of disclosure.

The fact that a conversation took place on a personal device rather than a company system does not take it outside the scope of disclosure. What matters is whether the document is relevant to the issues in the dispute and within the party's control. Using a personal phone does not exempt relevant business records from disclosure. What is required depends on control, the applicable order and proportionate safeguards for private or privileged material.

In Lloyds Developments Ltd v Accor Hotel Services UK Ltd [2024] EWHC 1238 (TCC), the court required an independent review of the claimant's WhatsApp disclosure because its presentation and redactions made it difficult to understand. The later 2026 judgment in the same litigation ([2026] EWHC 1522 (TCC)) addressed access to former directors' personal phones, with legal rights, privacy safeguards and technical limits all relevant. In Cabo Concepts Ltd v MGA Entertainment (UK) Ltd [2026] EWHC 768 (Ch), the court considered issues arising from the collection and disclosure of electronic material including mobile device content, and criticised deficient collection and supervision. These cases are a reminder that courts expect parties to take their disclosure obligations seriously from an early stage.

The practical step is to identify, at the outset, who in the business may have relevant communications on personal devices and to ensure those devices are not wiped, replaced or reset until the position has been considered properly.

Screenshots are not worthless. They can be useful as a quick record of what a message said at a particular moment. But they are not a substitute for preserving the original.

The original message carries metadata: the sender, the recipient, the timestamp, the device from which it was sent, and in some cases the read receipt. A screenshot captures the visible text but loses most of that context. Specialists may recover material from available device data, backups or another participant's copy, but recovery is not guaranteed. Some deleted messages cannot be recovered.

Where a message is relevant, the aim should be to preserve it in its native format — on the device or platform where it exists — rather than simply photographing the screen. If the device needs to be handed to a specialist for extraction, that should be done by someone who understands how to preserve the data without altering it. Disabling disappearing messages does not itself save messages already set to expire: preserve relevant existing material promptly.

Attempting to extract or copy electronic evidence without the right knowledge can inadvertently alter metadata and create problems later. If there is any doubt, take advice before touching the device.

Many businesses and individuals have automatic deletion or retention settings running in the background. Once a dispute is in prospect, those settings need to be reviewed and, where necessary, paused.

Email systems are often configured to delete items from deleted folders or to archive and purge messages after a set period. If that process continues after the duty to preserve has arisen, relevant material may be lost.

WhatsApp has a disappearing messages feature which, if enabled, will delete messages after a set time. If a relevant conversation is subject to that setting, the messages will be gone unless the feature is turned off and the existing messages are preserved. Disabling the feature does not itself save messages already set to expire.

Microsoft Teams and Slack both have retention and deletion policies which may be set at an organisational level. IT or compliance teams should be asked to check whether any relevant channels or conversations are subject to automatic deletion.

Phone upgrades are another risk. When a device is replaced and the old one is reset or returned to a carrier, any data not backed up may be permanently lost. If a dispute is in prospect, do not replace a device which may hold relevant material until the data has been properly preserved.

Cloud backups can be helpful, but they are not a complete answer. Backup schedules vary, and a backup taken before a relevant message was sent will not contain it. The original device or account remains the primary source.

Under CPR 31.6, standard disclosure requires a party to disclose documents on which they rely, documents which adversely affect their own case, adversely affect another party's case, or support another party's case. However, the required disclosure depends on the applicable regime and any court order. CPR Part 31 does not apply to small claims. In the Business and Property Courts, Practice Direction 57AD has its own disclosure duties and ordered models which apply instead of most of Part 31. The starting point is always the applicable regime and what the court has ordered.

Disclosure obligations can continue as the case develops. If a further document falls within the applicable disclosure duties, it must be dealt with under those duties and the court's directions. Privilege may justify withholding inspection or production; disclosure of a document's existence is distinct from allowing the other party to inspect its contents.

The existence of an adverse document is not, by itself, fatal to a case. Courts are accustomed to weighing evidence which points in different directions. What courts take seriously is the concealment or destruction of adverse material.

The practical advice is to identify adverse documents early, understand what they say and what they mean for the case, and take advice on how to deal with them. Trying to make them disappear is not a strategy.

Legal professional privilege protects certain communications from inspection by the other side. It does not mean those documents do not exist, and it is not a reason to destroy them. Existing legal advice may be privileged. Before sharing it for a review, consider the basis on which it can be shared without waiving protection.

Privileged documents may need to be identified and addressed in the disclosure process, even though the other party is not entitled to inspect them. The required description or notice depends on the disclosure regime and order; it is not always an individual entry for each communication. Failing to address a privileged document appropriately is not the same as being entitled to withhold it — where a privileged document falls within the applicable disclosure obligations, follow the required description or notice procedure while maintaining the claim to privilege.

Privilege can be lost. Forwarding legal advice to third parties, sharing it in a group chat or circulating it more widely than necessary can all create arguments that privilege has been waived. Once lost, privilege cannot generally be reasserted. Confidentiality and legal professional privilege are different.

The practical guidance is to keep legal advice within the group of people who genuinely need to see it, and to take advice before sharing it outside that group.

Disclosure is not limited to the documents held by the person managing the dispute. It extends to documents held by any person whose documents are within the party's control.

In a business context, that will typically include: directors and senior management involved in the relevant transaction or relationship; finance and accounts teams who handled invoicing, payment or financial reporting; sales and commercial teams who negotiated or managed the contract; operations and delivery teams who performed or received the relevant services or goods; and, where accessible, former employees who were involved at the relevant time.

The process of identifying relevant custodians — the people who may hold relevant documents — is one of the first steps in any properly conducted disclosure exercise. It should happen early, before documents are lost through routine deletion or device replacement.

Preservation and production are different things.

The obligation at the outset is to preserve relevant material so that it is available if it is needed. That does not mean immediately reviewing every email in the business or producing every document to the other side. Take reasonable steps to preserve material that may be relevant, including adverse material, and suspend deletion processes affecting it. Identify the relevant people, systems and period. If relevance is uncertain, preserve the material pending advice. A proportionate preservation plan is preferable to indiscriminate retention of every record indefinitely.

Disclosure in litigation is subject to proportionality. Practice Direction 57AD in the Business and Property Courts requires parties to consider the most appropriate disclosure model for the issues in the case, and the costs of disclosure must be proportionate to what is at stake.

The sensible approach is to identify the likely custodians and document sources, take steps to ensure that automatic deletion is paused, and then carry out a structured review when the scope of the issues is clearer. Rushing to collect everything at once, without a plan, tends to generate cost without generating clarity.

The consequences of disclosure failures range from adverse costs orders to adverse inferences at trial.

Where a party has failed to preserve or disclose relevant electronic material, the court may draw an inference that the missing material would have been adverse to that party's case. In serious cases, the court may strike out a claim or defence, or make an unless order requiring compliance on pain of dismissal.

In Lloyds Developments Ltd v Accor Hotel Services UK Ltd [2024] EWHC 1238 (TCC), the court required an independent review of the claimant's WhatsApp disclosure because its presentation and redactions made it difficult to understand. The later 2026 judgment ([2026] EWHC 1522 (TCC)) addressed access to former directors' personal phones. Cabo Concepts Ltd v MGA Entertainment (UK) Ltd [2026] EWHC 768 (Ch) concerned serious disclosure failings on both sides and an attempt to revisit an earlier adjournment costs order. The court criticised deficient collection and supervision, but did not find the solicitor had knowingly or recklessly misled the court, and refused to vary that earlier costs order. These cases illustrate that courts in the Business and Property Courts are prepared to examine electronic disclosure carefully and to take a robust approach where obligations have not been met.

Not every disclosure failure leads to sanctions. Courts will consider the nature and cause of the failure, whether it was deliberate, and what prejudice it has caused. But the risk is real, and the cost of getting it wrong — in terms of both the litigation outcome and the costs consequences — can be significant.