Absence Warning Letters Under the Acas Code

This guide covers England, Scotland and Wales. Section 10 of the Employment Relations Act 1999 and section 207A of the Trade Union and Labour Relations (Consolidation) Act 1992 extend to those three nations (legislation.gov.uk: s10, s207A). Northern Ireland has its own disciplinary rules and a Labour Relations Agency Code of Practice; see nidirect.

The letters below are examples to adapt to your own procedure and the facts of each case. They are not legal advice.

Which letter when

Before any of these, Acas says an employer should first see whether the problem can be resolved informally, for example by talking privately with the employee and agreeing improvements (Acas, disciplinary procedure step by step). Reaching an absence trigger point should start an absence review, not disciplinary action (Acas, absence trigger points). Our absence policy guide covers the review.

What the Acas Code requires first

The Code is the minimum an employer should follow for discipline and grievance. It mainly applies to employees (Acas). It was issued in 2015. Acas consulted on a draft updated Code from 30 July to 23 September 2026 and is reviewing the responses, so the 2015 Code still applies (Acas consultation).

The Code asks employers to (Acas Code, paragraphs 4 to 12):

• Investigate without unreasonable delay to establish the facts. In misconduct cases, where practicable, different people should carry out the investigation and the disciplinary hearing. An investigatory meeting should not by itself result in disciplinary action (paragraphs 5 to 7).
• Tell the employee in writing if there is a case to answer, with enough information about the alleged misconduct and its possible consequences for them to prepare. It would normally be appropriate to include copies of written evidence, which may include witness statements. Give the time and place of the meeting and the right to be accompanied (paragraphs 9 and 10).
• Hold a meeting without unreasonable delay, while allowing reasonable time to prepare. Explain the complaint and go through the evidence. Let the employee set out their case, ask questions, present evidence and call relevant witnesses (paragraphs 11 and 12).
• Decide and confirm in writing whether disciplinary or other action is justified (paragraph 18).
• Allow an appeal against any formal decision (paragraph 4).

Evidence to attach

The Acas guide says to have the relevant facts available, such as disciplinary records and other relevant documents, for instance absence or sickness records, and written witness statements where appropriate. Copies of relevant papers and all witness statements should be given to the employee in advance (Acas guide to discipline and grievances at work). For absence, that usually means the dates of each absence, notes of return-to-work interviews and absence reviews, and the policy the employee is said to have broken. Send only the health details the case needs; the ICO says employers must not collect more health information than they need (ICO, workers' health information).

The 25% adjustment

A failure to follow the Code does not by itself make an employer liable to proceedings, but employment tribunals take it into account (Acas Code, foreword). If a tribunal finds that the employer unreasonably failed to comply with the Code, it may increase any award to the employee by no more than 25%, where it considers this just and equitable. If the employee unreasonably failed to comply, it may reduce the award by up to 25% (TULRCA 1992, s207A(2) and (3)). This applies to the claims listed in Schedule A2, which include unfair dismissal (Schedule A2).

Invitation to a meeting

Send this once the investigation shows there is a case to answer. It follows the Acas sample letters and the hearing letter templates (Acas, disciplinary hearing letter templates).

First written warning

Where misconduct is confirmed it is usual to give a written warning. A first or final written warning should set out the nature of the misconduct and the change in behaviour required, with a timescale, and say how long the warning will remain current (Acas Code, paragraphs 19 and 21). The Acas guide gives as an example a first written warning valid for up to six months and a final written warning for 12 months, and says warnings should be disregarded after a specified period of satisfactory conduct (Acas guide). Set your own periods in your procedure.

Final written warning

A further act of misconduct within the set period would normally result in a final written warning. If a first issue is serious enough, it may be appropriate to move straight to a final written warning. The letter should tell the employee the consequences of further misconduct within the period, for example that it may result in dismissal or another contractual penalty such as demotion (Acas Code, paragraphs 19 to 21; Acas, disciplinary outcome letter templates).

Outcome and right of appeal

An employee who feels the action is wrong or unjust should appeal, letting you know the grounds in writing. Hear the appeal without unreasonable delay and, wherever possible, by a manager not previously involved in the case. Workers have a statutory right to be accompanied at appeal hearings. Tell the employee the result in writing as soon as possible (Acas Code, paragraphs 26 to 29). Acas publishes letters to arrange an appeal meeting and give its result (Acas, disciplinary appeal letter templates).

The right to be accompanied

Where a worker is required or invited to a disciplinary or grievance hearing and reasonably asks to be accompanied, the employer must allow one companion chosen by the worker who is (Employment Relations Act 1999, s10):

• employed by a trade union as an official;
• a trade union official whom the union has reasonably certified in writing as having experience of, or training in, acting as a companion; or
• another of the employer's workers.

The companion may put and sum up the worker's case, respond on the worker's behalf to any view expressed at the hearing, and confer with the worker. They do not have to be allowed to answer questions for the worker (s10(2B) and (2C)). If the companion cannot attend at the time proposed, the employer must postpone the hearing to a time the worker proposes, if it is reasonable and falls within 5 working days beginning with the first working day after the day the employer proposed (s10(4) and (5)). The employer must allow a worker time off during working hours to accompany a colleague (s10(6)).

The Code says the right applies where the meeting could result in a formal warning or other disciplinary action, or the confirmation of one at appeal. There is no statutory right to be accompanied at an investigatory meeting, though your procedure may allow it. A request does not have to be in writing (Acas Code, paragraphs 7, 13 and 15).

Genuine ill health

Acas guidance says a distinction should be made between absence on grounds of illness or injury and absence for no good reason, which may call for disciplinary action. Where absence is due to medically certificated illness, the issue becomes one of capability rather than conduct. Employers need to take a more sympathetic approach, particularly if the employee is disabled and reasonable adjustments might enable them to return (Acas guide, Appendix 4).

Capability, which includes capability assessed by reference to health, and conduct are separate potentially fair reasons for dismissal (Employment Rights Act 1996, s98(2) and (3)). So the warning letters above are for conduct, such as not following the reporting rules or absence without an acceptable reason. For an employee who is genuinely ill:

• Use a capability procedure. The Code says this about poor performance: an employer may deal with it under a separate capability procedure, but the basic principles of fairness in the Code should still be followed, adapted as needed (Acas Code, paragraph 1). Following the same principles for ill health is Acas good practice: the Acas guide treats certificated illness as a capability matter, to be handled with a more sympathetic approach (Acas guide, Appendix 4).
• An employer must not discipline someone just because they are disabled. Before a capability procedure, make sure you have done all you reasonably can to support them, including reasonable adjustments (Acas, capability when someone is disabled).
• For frequent short-term self-certified absence with no medical support, the Acas guide suggests asking the employee to see a doctor first, to find out whether treatment is needed and whether the cause is work-related (Acas guide, Appendix 4).

Letters in a capability process should talk about attendance, support and adjustments, not misconduct. A return-to-work interview after each absence is where most of these facts first come to light. Our employment law guide covers the Equality Act sections on disability and pregnancy.

Sources

1. Acas, Code of Practice on disciplinary and grievance procedures, in force from 11 March 2015; consultation on a draft updated Code, closed 23 September 2026.
2. Acas, Discipline and grievances at work: the Acas guide, including Appendix 3 (sample letters) and Appendix 4 (dealing with absence).
3. Acas, Disciplinary procedure step by step, last updated 4 December 2025.
4. Acas, Disciplinary hearing letter templates, outcome letter templates and appeal letter templates.
5. Acas, Absence trigger points; Capability and performance when someone is disabled.
6. Employment Relations Act 1999, section 10, legislation.gov.uk.
7. Trade Union and Labour Relations (Consolidation) Act 1992, section 207A and Schedule A2, legislation.gov.uk.
8. Employment Rights Act 1996, section 98, legislation.gov.uk.
9. ICO, Data protection and workers' health information.

Sources checked on 11 November 2026. This page is general information, not legal advice.