Disciplinary Investigations

All you need to know about disciplinary investigations:

Most managers will, at some stage, have to deal with misconduct by a member of staff. When doing so, it is important to ensure that a fair procedure is followed, or any resulting dismissal will almost inevitably be considered unfair by an employment tribunal, assuming that the individual satisfies the eligibility criteria for bringing an unfair dismissal claim.

This note explains the key stages in a disciplinary process, including how to carry out a fair and thorough investigation, how to conduct a disciplinary hearing, and the principles of fairness set out in the Acas Code of Practice on Disciplinary and Grievance Procedures (the Acas Code) and established by case law.

The note also considers common problems such as reluctant witnesses, the correct approach when an employee refuses to attend a disciplinary hearing, and how to proceed when a disciplinary matter has also resulted in criminal charges.

Key legal principles

Disputes concerning the conduct of disciplinary investigations and hearings most commonly arise in unfair dismissal claims under the Employment Rights Act 1996 (ERA 1996), including constructive unfair dismissal claims. It follows that, before commencing any disciplinary process, an employer needs to be familiar with the following:

  • The rules on who can bring a claim for unfair dismissal, in particular the two-year length of service requirement (section 108, ERA 1996).
  • The principles of fairness set out in the Acas Code of Practice on Disciplinary and Grievance Procedures (the Acas Code) and the supporting non-statutory guide, Discipline and grievances at work (the non-statutory Acas guide).
  • How to dismiss fairly, including the need to identify a statutory fair reason for dismissal (section 98(1), ERA 1996) and act reasonably in accordance with section 98(4), ERA 1996

The conduct of disciplinary investigations and hearings occasionally also gives rise to other claims. For example:

  • An employee might allege that their disciplinary process has been conducted less favourably than a comparator’s disciplinary process because of a protected characteristic, therefore amounting to unlawful direct discrimination under the Equality Act 2010.
  • In cases involving disability an employee might allege that a duty to make reasonable adjustments arose in relation to the conduct of their disciplinary process.
  • Breach of contract if the employer’s disciplinary procedure is contractual.

Who can claim unfair dismissal?

The requirements and best practice detailed in this practice note largely originate from the statutory protection against unfair dismissal. Accordingly, strictly speaking, the requirements will usually only apply if the employee satisfies the eligibility requirements to make an unfair dismissal claim.

If the employee does not satisfy those requirements, an employer could choose to adopt a less rigorous approach to the conduct of a disciplinary process involving such an employee. In practice, the requirement for an employee to have two years’ service is likely to be the key eligibility requirement.

Practitioners must also carefully assess whether any other potential claims, such as discrimination, might exist. If an employee alleges that they have been dismissed because of a protected characteristic, it is common for employment tribunals to be more receptive to such a claim if the employer has not followed a fair disciplinary process.

Acas Code of Practice

The Acas Code is intended to provide practical guidance to employers and employees on how to fairly carry out disciplinary procedures for misconduct or poor performance.

Failure to follow any part of the Acas Code does not of itself make an employer liable to proceedings. However, employment tribunals must take the Acas Code into account where relevant when considering whether an employer has acted reasonably or not (section 207, Trade Union and Labour Relations (Consolidation) Act 1992 (TULRCA)).

Furthermore, if the employee wins an unfair dismissal case (or one of a number of other types of case) the tribunal can adjust the amount of compensation by up to 25% either way, if either the employer or employee has unreasonably failed to comply with the Acas Code (section 207A, TULRCA).

The Acas Code is supplemented by the non-statutory Acas guide. Unlike the Acas Code, this does not need to be taken into account by tribunals, and neither can parties be penalised for failure to follow it. However, it does provide practical guidance on the handling of disciplinary matters, based on good industrial relations practice and the accumulated wisdom of several decades of unfair dismissal law.

Fair dismissal

When determining if a dismissal is fair or not, a tribunal will consider two key issues.

Firstly, the employer must establish the principal reason for the dismissal and demonstrate that it falls within one of the categories of potentially fair reasons in section 98 of the ERA 1996, which include capability, conduct, redundancy or “some other substantial reason” (SOSR).

Secondly, it will be necessary for an employment tribunal to apply the test under section 98(4) of the ERA 1996: taking into account all the circumstances of the case, did the employer act reasonably in treating the given reason for dismissal, or reasons, as sufficient to justify dismissing the employee?

Over time this has been interpreted by the courts as including a requirement that an employer adopt a fair procedure before taking the decision to dismiss.

For example, with regard to conduct and capability, a fair procedure translates into the fair, transparent and consistent application of a disciplinary or capability procedure, where the employee is informed of the case against them, has the opportunity to present their side of events at a hearing, and has the right of appeal against dismissal.

‘Burchell Test’

In misconduct cases, an employment tribunal will apply the Burchell test:

  • Did the employer genuinely believe the employee to be guilty of misconduct?
  • Did the employer have reasonable grounds for believing that the employee was guilty of that misconduct?
  • At the time it held that belief, had the employer carried out as much investigation as was reasonable?
  • In addition, dismissal must be within the range of reasonable responses.

Informal discussions and warnings

Informal discussions with, for example, an employee whose timekeeping may be giving cause for concern, may be all that is needed to alert the employee to the fact that their lateness has been noticed and is not acceptable.

This can often be a better way of dealing with the problem than launching straight into an investigation and formal disciplinary action.

Obviously, if this approach is unsuccessful and the lateness continues, a more thorough investigation may be necessary, and will involve the employer in keeping records of the lateness in order to provide evidence at a disciplinary hearing.

Informal action is often a very useful tool in cases of poor performance. The employee and manager may be able to have a constructive conversation about the areas of concern and additional coaching, training, and advice may be sought and/or provided.

An employer should ensure that the employee is made aware that formal processes could be commenced if the problem does not resolve itself or the level of performance required is not maintained; an informal warning can serve as evidence of this.

At most, an informal warning serves as a warning that a disciplinary procedure might be commenced in the future, if there is a repetition of the unsatisfactory behaviour.

Any warnings given at this stage should be verbal and strictly “informal”. The fact that a ‘warning’ has been issued should not be confirmed in writing.

This is not to say that managers cannot keep a note of these informal discussions with employees and any informal verbal warnings they have given. Otherwise, they will not be an effective management tool. Moreover, failure to document informal warnings and discussions may also create problems in evidencing that the disciplinary process has been followed.

Suggested informal steps

  • Holding a confidential, private meeting with the employee to highlight the problem.
  • Enquiring why the problem has arisen: for example, frequent absence may be due to personal or health problems, or a relationship difficulty at work.
  • Agreeing what action is needed.
  • Keeping a record of the conversation.
  • Sending a memo to the employee setting out what has been agreed or decided and saying that disciplinary action will follow if there is no change in their conduct.

Employers should not use informal procedures where the conduct, if proven, could result in dismissal.

Commencing a disciplinary process: planning

If informal action has not resolved an issue, or if the issue is too serious for informal resolution, the employer will need to commence formal processes.

At its simplest, planning will mean:

  • Checking the requirements of the employer’s disciplinary policy.
  • Choosing an appropriate investigator.
  • Keeping in mind the general requirement of having different people at each stage (that is, the investigation, disciplinary meeting and appeal meeting) in ascending seniority.
  • Keeping to timescales in disciplinary policies and avoiding unreasonable delay
  • Having regard to the interplay with any related processes (for example, any related grievance process).

The allegation

From the outset, it is important to correctly frame the allegation(s) against the employee, for a couple of reasons.

Firstly, the content of the allegation will, in turn, frame the investigation.

Secondly, it is a fundamental principle of fairness that the employee knows the allegation against them. This principle is relevant both at the outset of the investigation and afterwards, if the employer decides to proceed to a disciplinary hearing.

The investigation

The requirement for an investigation to take place prior to any disciplinary action is critical. In all but the rarest of cases, failure to do so will fall foul of the Acas Code or the principles of fairness established by case law. This is true even in cases of apparently “obvious guilt” and, potentially, where the employee admits guilt.

Employee admits guilt: An admission is likely to shape the investigation that the employer then follows but may not remove the need for further investigation to be undertaken. For example, an investigation might reveal mitigating circumstances that lessen the level of culpability.

How much investigation is required?

Whilst nearly every case will require an investigation, the amount of investigation required will vary enormously depending on the individual circumstances of the case.

The legal test is that an employer must hold such investigation as is “reasonable in all the circumstances”, judged objectively by reference to the “band of reasonable responses” (Sainsbury’s Supermarkets Ltd v Hitt [2002] EWCA Civ 1588).

The non-statutory Acas guide states that the more serious the allegation, the more thorough the level of investigation required.

This will depend on the gravity of the allegation and the potential effect on the employee. So, if an employee’s professional reputation or ability to work in a chosen career is at stake, it is even more important that the investigation is fair and even-handed.

While it is difficult to give hard and fast guidelines as to what this means in practice, an employer will need to investigate sufficiently to ensure that the substance of the allegations are clear, in order that these can be put to the employee in sufficient detail to enable a meaningful response.

It is not necessary for an employer to extensively investigate each line of defence advanced by an employee. What was important was the reasonableness of the investigation as a whole.

Who should conduct the investigation?

Once the decision is taken that an investigation is required, the employer needs to consider who should conduct the investigation.

In most cases, the employee’s immediate line manager will be the appropriate person. However, this may not always be the case. Sometimes the employer’s own procedure (which may be contractual) stipulates who is to conduct an investigation.

An alternative is to appoint a member of the human resources department to conduct the investigation, since they may have had training as to the best way to go about this.

In other cases someone with specialist knowledge may be needed, for example, a finance manager, if the allegations concern financial mismanagement.

The investigator should ideally not be a key witness (unless this is completely unavoidable, for example, in the case of a small employer).

When selecting the investigator, the employer will also need to consider who should conduct the disciplinary hearing, if one becomes necessary, and any potential appeal hearing.

The role of HR

Human Resources should make sure the advice it gives to the investigator is limited to questions of law, procedure and process, and does not stray into areas of culpability.

If this remit is exceeded, then there is a danger that the fairness of the investigation process could be compromised, which could result in an unfair dismissal.

The criticisms made of HR unfair influence arose in cases where a non-HR person had been appointed as investigator. The sense was that HR was interfering or manipulating that investigator’s conclusions. Whilst the cases do not expressly say so, they ought not to prevent a designated HR officer being appointed as the investigator, particularly, for example, if they are the best placed person in the employer’s organisation and this is consistent with the employer’s policy and practice.

A right to be accompanied?

Employees have no statutory right to be accompanied at an investigatory meeting, however, check that the relevant policy or contract of employment does not give a right to this.

Employers should also bear in mind their obligations to disabled employees under discrimination legislation, which provides that employers must make reasonable adjustments where their premises or working practices put a disabled person at a substantial disadvantage in comparison with others.

Such adjustments could apply to meetings held by way of an investigation hearing and could include allowing an employee with a disability to be accompanied, where there was no such contractual right, and by someone other than a colleague or trade union official.

The Acas investigations guide advises that in many cases it will benefit an investigation to allow an employee to be accompanied at an investigation meeting. It also suggests that employers might even consider allowing a friend or family member to accompany an interviewee (page 19, Acas investigations guide).


Before commencing an investigation, the employer should always bear in mind the importance of keeping the investigation confidential.

This duty applies to both the person conducting the investigation and to any witnesses.

Consideration should be given as to whether fellow employees interviewed as witnesses need to be told the name of the employee being investigated. Obviously, this cannot be avoided in small offices and in situations of individual misconduct but there will be cases in which it is possible to gather information without revealing names.

In any event, witnesses should be advised not to discuss the investigation with other employees or third parties and, where appropriate, be reminded of their legal duties of confidentiality.

In contrast, there is no set rule on whether an employer has a duty of confidentiality to witnesses providing information in disciplinary investigations. Whether it is required in a particular case will depend on the nature of the disciplinary charge, the other evidence in the case and the strength of any balancing considerations that support or justify non-disclosure

Obtaining the evidence

Any investigation undertaken by the employer should ideally be conducted as quickly as is reasonably possible. The Acas Code says that it should happen “without unreasonable delay” (paragraph 5).

Witnesses should be spoken to and notes taken of their recollection of events before memories fade.

Consideration also needs to be given as to whether any physical evidence is required.

The type of physical evidence required will obviously depend on the issue to be determined:

  • if there is a suspicion the employee has been disclosing confidential information to competitors, the employee’s correspondence files and emails may need to be searched.
  • If the employee has a company mobile phone, checks may need to be undertaken as to what numbers were dialled.
  • It may be appropriate for the employer to review its CCTV recordings, particularly when this has been requested by the employee.

Covert surveillance

Care should be taken with respect to any evidence gathered as a result of recording an employee’s activity, such as surveillance film.

Any surveillance recordings purporting to show that an employee on sick leave might be fit for work should be assessed by a medical professional with appropriate qualifications. A failure to have do so is likely to render the investigation unreasonable.

Covert surveillance can also lead to a breach of employees’ right to privacy under the Human Rights Act 1988 and the European Convention on Human Rights (ECHR).

There is a clear balance to be struck between the employer’s need to gather information for the investigation and the employee’s right to be treated fairly and reasonably so that there is no breach of the implied term of mutual trust and confidence.

An employer should therefore be careful to not use the investigation as an excuse to undertake a “fishing expedition” and should avoid reading material that is obviously personal such as private emails and diary entries.

Witness evidence

The evidence of witnesses is often crucial to the investigation, particularly in cases of misconduct. Witnesses should be interviewed privately and the need for confidentiality should be emphasised. Notes should be made of the statement or of the information provided by the witness and where possible the witness asked to sign the statement to confirm that the version of events taken down by the interviewer is correct.

For guidance on witness statements click >>here<<

Reluctant witnesses

A common problem faced by employers is that of the reluctant witness or the witness who will only provide information if they are given an assurance of anonymity.

The employer should try to establish the reason for any reluctance and, if the witness is an employee, then they should be reminded of the obligation of good faith or fidelity owed towards the employer.

However, while it may be possible to establish an implied obligation for senior managers to report on another employee’s misconduct, it is unlikely, in the absence of an express obligation, that a junior employee would be legally obliged to inform on a colleague.


When a witness requests anonymity the reason for the request and the motives of the informant need to be explored.

If a tribunal is asked to rule on whether a subsequent dismissal was fair, it must consider whether the employer’s investigation was within the band of reasonableness. In doing so it should investigate why there was a need for anonymity and carry out a balancing act between that perceived need and the employee’s need to know details of the case against him.

In a small workplace, or in instances where the witness is genuinely in fear of physical violence, various steps can be taken to protect a witness’s identity. The reality is, however, no guarantee of complete anonymity to the witness can be given. There may always be a risk that subsequent criminal or civil (including employment tribunal) proceedings are issued and the accused employee will seek disclosure of the witness statements or notes of interview, which will identify the witness.

It is possible to anonymise witness statements in disciplinary proceedings but this should only be done where:

  • the witness is giving evidence about wrongdoing that is unrelated to them
  • the witness has a genuine fear of reprisal and
  • there is good reason to believe that the witness evidence would not have been provided unless the witness had been assured of anonymity.

For disciplinary proceedings to be fair, it is important that the employee knows the case they have to answer. They need to know what allegations have been made against them in order that they can respond to them. So anonymity should only be allowed in exceptional circumstances.

In such a case HR advise must be sought, so that all steps possible to avoid prejudice to the employee are implemented.

Investigations are not disciplinary hearings

Employers need to be aware that there is a distinction between an investigation and any subsequent disciplinary proceedings. For example, if an employee admits guilt during an investigative interview this will not remove the need for a further disciplinary meeting, in order that the employee can have an opportunity to state his case and possibly bring evidence to explain any mitigating factors.

Investigation report

It will usually be helpful for the investigating officer to prepare a report summarising the steps taken in the investigation, the allegations, and the evidence available in respect of them which may assist with the conduct of the disciplinary hearing.

The Acas investigations guide advises that an investigation report should include:

An introduction setting out:

  • The name and job title of the person who authorised the investigation.
  • The name and job title of the person who conducted the investigation.

A brief overview of the circumstances that led to the investigation.

The terms of reference of the investigation and if they were amended.

The investigation process followed, including:

  • How the investigation was conducted.
  • What evidence was collected.
  • Whether any pieces of evidence could not be collected and why.
  • The names and job titles of all witnesses and why each witness was relevant to the matter.
  • Whether any witnesses could not be interviewed and why.
  • An explanation of why any witness’s statement has been anonymised and providing any details of enquiry into their character and background.

The investigation findings, including a summary of the:

  • Findings from all relevant documents.
  • Key evidence from each witness statement.
  • Facts that have been established and, what facts have not been established.

Mitigating factors to consider, if any.

The report’s conclusions, including the investigator’s recommendations based on all evidence collected and any other recommendations related to the matter.

Copies of all documents and witness statements collected and referred to in the report.

Is further action required?

At the end of the investigation the person who made the decision to appoint the investigating officer should then decide what the next steps should be, in view of the investigation findings.

Generally, this will mean deciding whether the investigation findings warrant progressing to a disciplinary hearing or not. This is likely to involve similar considerations to those that apply at the earlier stage of deciding whether to even initiate a formal investigation (see Is formal action necessary?).

Information to be given to the employee before the disciplinary hearing

Once the investigation is complete, if the employer decides that formal disciplinary action is required, it should write to the employee to confirm the outcome of the investigation and invite them to a disciplinary hearing.

The letter should set out sufficient information about the allegations and their possible consequences to enable the employee to prepare their case for the disciplinary hearing (paragraph 9, Acas Code).

Copies of any documents or evidence on which the employer intends to rely at the hearing should be provided, together with the names of any witnesses who will attend (paragraph 12, Acas Code).

It is advisable to send the employee a copy of the employer’s disciplinary procedure, so that the employee understands the process.

The Acas Code advises employers to inform the employee in writing of the right to be accompanied (paragraph 10, see Right to be accompanied).

The disciplinary invitation letter should also set out the arrangements for the disciplinary hearing.

The disciplinary hearing should be convened at a reasonable time and place. It should certainly be conducted during normal working hours and consideration should be given to its location.

If the matter is of a particularly sensitive or confidential nature it may be advisable for the meeting to be conducted away from the employee’s place of work.

An employee should be given sufficient time to consider the allegations and to read any witness statements and other investigation materials.

The employee should also be asked if there are any witnesses they wish to call to the hearing and any documents they wish to rely on that have not already been disclosed.

If the employee is still working, the letter, and any accompanying documents, should be given to them in person.

If the employee is on suspension, the employer should consider using a courier to deliver the letter, rather than relying on the post. If not, recorded or registered mail and a copy to a private email address (if known) should be used to prevent any allegation that the letter was not received by the employee.

Setting out the case against the employee

It is a principle of natural justice that an accused person must be informed of the charges against them so that they have the opportunity to put their side of the story:

”It is a fundamental part of a fair disciplinary procedure that an employee know the case against him. Fairness requires that someone accused should know the case to be met; should hear or be told the important parts of the evidence in support of that case; should have an opportunity to criticise or dispute that evidence and to adduce his own evidence and argue his case.”

(Spink v Express Foods Ltd [1990] IRLR 320 (EAT)).

The employer should ensure that the letter requesting the employee’s attendance at any disciplinary hearing accurately sets out the allegations against them.

Employers should not accuse an employee of one thing and dismiss for another reason, or frame the accusation in such broad terms as to mask its potential seriousness.

Precision is key: “the charge against… the employee facing dismissal should be precisely framed”, and the employee “should be found guilty, if he is found guilty at all, only of a charge which is put to him”

(Strouthos v London Underground [2004] IRLR 636 (CA)).

Employee should be aware of possible consequences

It is important to make sure the employee appreciates the severity of the allegations and the possible consequences. They should not be expected to work this out for themselves from the disciplinary policy. In particular, an employee who is at risk of dismissal must be told of this in advance of the hearing, otherwise the dismissal may be unfair. The employee needs to know that they are “fighting for their job”.

Disclosing the evidence

Ideally all witness statements and other documents to be relied on should be made available to the employee before the hearing. This helps to give the employee a full picture of the nature of the allegations and the case they have to meet. Obviously if the employer has given a promise of anonymity to any witnesses, steps will have to be taken to amend the witness statements for this purpose (see Reluctant witnesses).

Disciplinary Hearings

For detailed guidance on all matters relating to disciplinary hearings click >>here<<