Employment Tribunal Evidence: A Complete Guide

Evidence is the foundation of an employment tribunal claim. The tribunal cannot see what happened to you - it can only read the documents, hear the witnesses, and form a view based on what is put before it. The stronger your evidence, the better placed you are to tell your story accurately and persuasively.

This guide explains what counts as evidence, how to gather it, and what to do when your employer holds documents you need.

Why evidence matters - and who proves what

Different types of claim have different rules about who must prove what.

In an unfair dismissal claim, your employer must show the tribunal the reason for the dismissal and that it was a potentially fair reason - such as conduct, capability, or redundancy. Your role is then to show that the dismissal was unreasonable in all the circumstances, or that the reason given was not the real one.

In a discrimination claim under the Equality Act 2010, the burden shifts. Once you show facts from which discrimination could be inferred, it falls to your employer to prove the treatment was not discriminatory. Your evidence of how you were treated - especially compared to others in similar situations - is therefore central to the claim.

In either type of case, strong evidence helps the tribunal understand what happened, in what order, and who said what.

Types of evidence

Documentary evidence

Documents are usually the most reliable form of evidence because they were created at or close to the time of the events they record. Courts and tribunals treat contemporaneous documents as more credible than accounts reconstructed from memory months later.

Useful documents to collect include:

• Your employment contract and any subsequent written amendments
• Payslips and P60s
• Emails and letters between you and your employer
• Disciplinary and performance management records
• Investigation reports and notes
• Performance reviews and appraisals
• Meeting notes and agendas
• Policies, procedures, and handbooks your employer says you breached
• Sickness records and correspondence about your absence
• Written warnings, outcome letters, and appeal decisions
• Any redundancy selection matrix or scoring documents, if your claim involves redundancy

Collect these as early as possible. Once you leave a job, access to work systems is usually cut off quickly and emails may be deleted.

Witness evidence

Witnesses who saw or heard relevant events can provide written statements and give oral evidence at the hearing. A colleague who was present at your dismissal meeting, a manager who can confirm what policy actually applied, or someone who overheard a discriminatory comment can all provide valuable corroboration.

Not every witness has to be someone who agrees with your account. The tribunal will also hear from your employer's witnesses, and you will have the opportunity to question them on their statements.

Your own account

Your own written account of events is evidence. The tribunal will read your ET1 claim form and any witness statement you provide. Your account carries more weight when it is detailed, consistent with the documents, and grounded in specific dates and events.

Vague assertions are harder for a tribunal to act on than specific, documented incidents. Where possible, anchor your account to dates, names, and what was said or written.

The trial bundle

Before a hearing, both sides exchange their documents and compile them into a single trial bundle. This is a paginated folder - usually sent electronically in modern tribunal proceedings - containing all the documents both parties rely on.

The Employment Tribunals Rules of Procedure under SI 2013/1237 govern how this works in practice. The tribunal will issue case management directions setting out when documents must be exchanged, when witness statements must be served on the other side, and when the bundle must be lodged with the tribunal itself.

Both sides contribute to the bundle. If your employer includes a document you want to challenge, you can still refer to it. If a document you need is not in the bundle, raise it with the tribunal as early as possible.

For unrepresented claimants, the bundle process can feel daunting. The key discipline is organisation - keep every document you might want to rely on from the moment you think a tribunal claim is possible. Label them clearly and note where they came from.

See the guide to how to write your ET1 form for more on submitting your claim.

Getting documents from your employer - the DSAR

One of the most powerful tools available to you before a hearing is the Data Subject Access Request (DSAR) under UK GDPR Article 15 and the Data Protection Act 2018.

A DSAR lets you ask your employer for all personal data they hold about you. This can include:

• Emails about you - including those you were not copied on
• HR notes and management meeting records
• Notes made about you by any manager or HR professional
• Records of formal and informal meetings you attended
• Any automated decision-making records, such as a scoring system used in redundancy selection
• Any database entry that references you by name or identifier

Your employer must respond within one month. They can extend this by a further two months for complex or numerous requests, but they must tell you within the first month that they are doing so.

You do not need to explain why you are making the request. You do not need to say you are planning a tribunal claim.

The Information Commissioner's Office has detailed guidance on what a valid DSAR covers and what employers are permitted to withhold. Exemptions exist - for example, legal professional privilege - but employers cannot simply refuse to engage.

If your employer refuses to respond or provides an incomplete response, you can complain to the ICO. You can also raise the failure with the tribunal itself. Employers who fail to comply with a DSAR when litigation is anticipated may face adverse inferences about what those documents contained.

Send your DSAR as early as possible - well before you submit your ET1. The one-month response window means you need to plan ahead.

Emails and messages

Emails you sent or received on your personal email account are straightforwardly yours to use as evidence. Download them, export them, or take screenshots, and store them somewhere safe off your employer's systems.

Work email is more complicated. Once you leave a role, your email account will usually be deleted or archived and you will lose access to it. Download or forward anything relevant to your personal account before your last day. Many employers have policies against forwarding work emails to personal accounts - check yours. If forwarding would breach a policy, take screenshots instead.

WhatsApp messages, Microsoft Teams chats, and personal text messages are routinely accepted as evidence at employment tribunals. Export the relevant conversation thread and take screenshots with the date and time clearly visible. WhatsApp's export function produces a text file and any attached media, which is easier to produce as a document than scrolling screenshots.

Be careful about taking large volumes of data from work-owned devices or systems beyond what you reasonably need for your claim. The tribunal will look at how the evidence was obtained as well as what it says.

Covert recordings

A covert recording is one made without the other person's knowledge. UK employment tribunals are not bound by the same strict exclusionary rules as criminal courts - covert recordings are not automatically inadmissible.

Tribunals have discretion to admit covert recordings and will weigh the value of the evidence against the circumstances in which it was made. In cases involving serious misconduct - where a claimant had genuine reason to believe they were being treated unlawfully and made a recording to protect themselves - tribunals have admitted the evidence. In other cases, tribunals have found that recordings made without good reason damaged the claimant's credibility.

The principal risk is not legal admissibility - it is how the recording affects the tribunal's view of you as a witness. A recording made in an open meeting carries less risk than one made in a private one-to-one conversation. Making a recording without consent may also breach your employer's disciplinary policies and, in some contexts, data protection obligations.

The position is fact-specific. If you are considering making a recording, think carefully about the context and what you are trying to capture.

Keeping a contemporaneous diary

A written diary is one of the most valuable pieces of evidence you can create. Entries made at the time - the same day or the next morning - are treated by tribunals as far more reliable than an account reconstructed months later for a claim form.

In discrimination and harassment cases in particular, a detailed diary showing a pattern of behaviour over time can be persuasive evidence that a single incident would not be.

Note down:

• What happened, in plain factual terms
• The date and time
• Who was present
• What was said - direct quotes as close to accurate as you can manage
• How it made you feel and how it affected your work or health (relevant in discrimination and personal injury claims)

Store your diary somewhere your employer cannot access it - a personal email account, a secure note on your personal phone, or a printed paper diary kept at home.

Witness statements

For the hearing itself, every witness - including you - will be required to produce a formal witness statement. This is a written account signed with a statement of truth, confirming that the contents are true to the best of the witness's knowledge and belief.

Witness statements are usually read by the tribunal panel before the hearing begins. At the hearing, the statement stands as your evidence in chief - you do not normally read it aloud. The other side then has the opportunity to question the witness, and the tribunal panel may ask questions too.

A good witness statement is clear, chronological, and factual. It covers events the witness directly witnessed - not what they were told by others, not speculation about motives. It should be in the witness's own words and voice.

You have the right to call witnesses who can support your account. Anyone you want to call will need to produce their own statement and attend the hearing. Witnesses who are still employed by your former employer may be reluctant to give evidence - this is a practical challenge many claimants face. The tribunal cannot compel a private individual to attend, though it can issue a witness order requiring them to do so.

What to do if evidence has been withheld or destroyed

If your employer has failed to disclose relevant documents, or you have reason to believe documents have been deleted, raise this with the tribunal as soon as you become aware of it.

Tribunals can make orders requiring your employer to search for and disclose specific categories of documents. These are called disclosure orders or specific disclosure orders, and failure to comply with them is a serious matter.

Where a party fails to disclose documents without adequate explanation, the tribunal can draw an adverse inference. In practice, this means the tribunal may conclude that the missing documents would have supported your case - a powerful tool when you cannot access the documents directly.

Document every request you have made for documents and your employer's response to each one. Your DSAR response - or the absence of one - is itself evidence of what your employer was willing to produce.

ACAS guidance on preparing for a tribunal covers the broader process of getting ready for a hearing, including practical steps in the weeks before the date.

This guide contains legal information, not legal advice. Tribunal outcomes depend on the specific facts of each case. In similar situations, tribunals have approached evidence differently depending on how it was obtained, its relevance, and how it fits with the rest of the record. If you are unsure how the evidence rules apply to your situation, you may want to consider speaking to an employment law specialist.