One of the most common questions raised by both employees and employers is: how long does a disciplinary investigation take? The answer, perhaps frustratingly, is that there is no fixed timeframe (an exception may be if organisational policies specify a timeframe within which certain activities, such as the investigation, need to be completed). The duration of a disciplinary investigation can vary significantly depending on a range of factors, most notably the number of issues involved and the complexity of those issues. Understanding why timelines differ—and what is considered reasonable—can help manage expectations whilst ensuring that the necessary information is gathered as part of the investigation.
In essence, a disciplinary investigation is a fact-finding exercise. Its purpose is to establish what has happened, gather relevant evidence, and determine whether there is a case to answer. This stage is distinct from any subsequent disciplinary hearing, where decisions about potential sanctions are made. Whilst a disciplinary investigation should not be rushed it must also not be unnecessarily delayed, as prolonged uncertainty can place strain on all parties involved.
A significant factor influencing how long a disciplinary investigation takes is the number of issues being examined. A straightforward matter involving a single allegation—such as a breach of company policy—may be resolved relatively quickly. In contrast, cases involving multiple allegations, numerous witnesses, or overlapping incidents will naturally take longer.
Closely related to the number of issues is their complexity. Complexity can arise in various forms. For example, allegations involving technical evidence, such as financial irregularities, data misuse, or health and safety breaches, often require specialist knowledge or the involvement of a number of people. Similarly, situations involving conflicting witness accounts (such as when discrimination or harassment is alleged) may require additional interviews, due to the need to approach the issue with particular care.
Another important consideration is the availability of evidence and witnesses. Investigations cannot progress efficiently if key individuals are unavailable due to, for example, annual leave or sickness absence. Additionally, gathering documentary evidence—such as emails, reports, or CCTV footage—may take time, particularly in larger organisations where information is stored across different systems or departments.
Employers also have a duty to ensure that investigations are conducted impartially and thoroughly. This often means appointing an investigating officer who is independent of the matter and has not been directly involved in the events being investigated. In some cases, particularly where senior employees are involved, it may be useful to appoint an external investigator. While this can enhance objectivity, it can also extend the timeframe due to the need for onboarding and familiarisation with the organisation’s policies and procedures.
A key principle underpinning disciplinary investigations is reasonableness. The ACAS code of practice on Grievance and Disciplinary procedures sets out good practice principles. (for more information on What is the ACAS code of practice? Read our blog). The ACAS code of practice does not prescribe a strict deadline for completing investigations, but it does require employers to act without unreasonable delay. What is considered reasonable will depend on the circumstances.
Communication plays a critical role in managing the length of an investigation. Employees who are subject to a disciplinary investigation should be kept informed of progress and any anticipated delays. Clear communication helps to maintain trust in the process and reduces anxiety. It also demonstrates that the employer is actively progressing the matter rather than allowing it to drift. Regular updates, even if brief, can make a significant difference to how the process is perceived.
One area that often raises concern is whether an employee can continue working during the investigation. In many cases, employees should be able to remain in the workplace while the investigation is ongoing. This is particularly appropriate where there is no immediate risk to the business, other employees, or the integrity of the investigation. Allowing the employee to continue working can minimise disruption and help maintain normal working relationships.
However, there are situations where suspension may be considered necessary. Suspension is not a disciplinary sanction; rather, it is a neutral act intended to facilitate a fair investigation. For example, suspension may be appropriate where there is a risk that evidence could be tampered with, witnesses could be influenced, or the employee’s presence could pose a risk to others. Even in such cases, suspension should be used as a last resort and kept under regular review to ensure it remains justified.
Importantly, where an employee is suspended during a disciplinary investigation, they should receive full pay. This reflects the principle that suspension is not intended to be a punishment and that no findings have yet been made. For more information on suspension, read our blog Suspended at work will I get fired?
Employers should aim to complete investigations as quickly as reasonably possible to minimise periods of suspension. Regular reviews of the suspension decision are important, as is documenting reasons for continuing or lifting the suspension.
Another factor influencing investigation timelines is the need to engage with the employee’s case. Employees have the right to respond to allegations and to provide their own evidence. This process may result in further lines of enquiry in order to establish what happened.
Organisational factors can also play a role. Larger organisations may have more formal procedures and multiple layers which can extend timelines. Smaller organisations may be able to act more quickly but may lack dedicated HR resources. The experience and training of those conducting the investigation can also influence how efficiently it is carried out.
It is worth noting that delays are not always problematic. In some instances, taking additional time can enhance the quality and robustness of the investigation. For example, allowing time to gather comprehensive evidence or to resolve inconsistencies can lead to more accurate findings. The key is that any delay should be justified, proportionate, and clearly communicated to the employee.
From an employee’s perspective, prolonged investigations can be stressful and disruptive. This is particularly true where the employee has been suspended. Employers should therefore take steps to support employees during the process, such as providing access to employee assistance programmes or maintaining appropriate lines of communication.
In addition, obtaining professional advice can be highly beneficial for both employees and employers navigating a disciplinary investigation. Employees may wish to seek guidance to better understand their rights, prepare for investigatory meetings, and ensure that their responses are effective. Professional support can help employees engage confidently with the process and avoid misunderstandings.
For employers, engaging external expertise can also add value, particularly in more complex or sensitive cases. Independent advisors could undertake the investigation, ensuring compliance with policies etc. In some circumstances, organisations may choose to outsource elements of the process, such as appointing an external investigator to conduct interviews and compile findings.
Training is another area where professional support can make a meaningful difference. Ensuring that managers and investigating officers are properly trained in conducting disciplinary investigations can improve both the efficiency and fairness of the process. Well-trained staff are more likely to gather relevant evidence effectively, ask appropriate questions, and document findings clearly, all of which can help avoid unnecessary delays. In this way, investment in training can have a direct impact on how long investigations take and how robust their outcomes are.
Ultimately, whether through advisory support, training, or the outsourcing of investigative tasks, professional assistance can streamline the process, and improve confidence in the outcome for all parties involved.
Employers should strive to progress investigations efficiently while ensuring that all relevant evidence is considered and that employees are given a fair opportunity to respond. Where possible, employees should be able to continue working during the investigation. If suspension is necessary, it should be used sparingly, kept under review, and accompanied by full pay. By adhering to these principles, organisations can ensure that their disciplinary processes are both effective and fair, regardless of the time they take to complete.
Plotkin & Chandler works exclusively in the areas of HR and employment law.
If you are an employer who would like advice on disciplinary matters, you would like assistance with carrying out an independent investigation, undertaking a disciplinary hearing, you would like to discuss training for your organisation or you need assistance on defending an Employment Tribunal claim, we can help.
If you are an employee and would like advice on the disciplinary process or you have been dismissed and would like to discuss bringing an Employment Tribunal claim, we can help. Please contact us on 020 3923 8616 to discuss your needs and requirements or email us on info@plotkinandchandler.com
