What does the ACAS Code of Practice require employers to do?

The short answer

The ACAS Code of Practice on Disciplinary and Grievance Procedures is a short statutory document that sets out the minimum fair process for handling workplace disciplinary issues and grievances in the UK. It is not optional: under section 207A of the Trade Union and Labour Relations (Consolidation) Act 1992, tribunals can increase a compensatory award by up to 25% if an employer unreasonably fails to follow it — or reduce an award by up to 25% if an employee unreasonably fails to follow it.

If you've seen a tribunal decision mention an "ACAS uplift" or "ACAS reduction," this is what it's referring to.

What the Code actually requires

The Code is deliberately short and principles-based. The core steps are:

For disciplinary cases

1. Establish the facts promptly. Carry out a fair and proportionate investigation. For most cases this is a single investigator who is independent of the eventual decision-maker.
2. Tell the employee in writing what the allegations are, supported by the evidence, in time for them to prepare.
3. Hold a hearing at which the employee can put their case, ask questions about the evidence, and be accompanied by a colleague or trade union representative.
4. Decide and communicate the outcome in writing, including any sanction.
5. Allow an appeal, heard by someone different from the original decision-maker, with a further meeting and a written outcome.

For grievances

1. Let the employer know about the grievance, in writing.
2. Hold a meeting without unreasonable delay, with a right to be accompanied.
3. Decide and communicate the outcome in writing.
4. Allow an appeal.

What "unreasonable failure" looks like in practice

The Code is not a checklist that the tribunal mechanically scores. The question is whether the employer's failure to follow it was unreasonable in the circumstances. The bigger the gap between what the Code requires and what the employer did, the higher the uplift.

Real awards show how this works in practice. In unfair dismissal with ACAS uplift, Riley Foods Limited failed to follow the Code on a dismissal — the tribunal added a full 25% uplift on top of a £14,965 award. The employer's failure was total: no compliance with the Code at all.

A partial failure usually gets less. In unfair dismissal win after employer ignored ACAS code, the tribunal applied a 10% uplift rather than the maximum — the employer's procedural failure was real but less complete. Award: £14,624.

Same pattern in sewing machinist wins £20,891 after being sole redundancy — a 20% uplift for breaching the Code in a redundancy process where the employer dismissed only one employee despite promising a mass layoff.

The ultimate "total failure" looks like unfair dismissal win after employer failed to respond to claim: employer didn't engage with the process, didn't defend the tribunal claim, hadn't followed the Code, full 25% uplift. £15,278.

When the uplift cuts both ways

The same provision (s.207A TULRCA) lets tribunals reduce an award by up to 25% if the employee unreasonably failed to follow the Code — for instance, by refusing to attend a properly-arranged disciplinary hearing or by not appealing without good reason. In practice this reduction is less common than the uplift because most procedural failures are on the employer side, but it does happen.

There can also be other deductions on top. In unfair dismissal for conduct: ACAS code uplift and Polkey reduction applied, the tribunal applied:

• A 20% ACAS uplift for the employer's procedural failure, plus
• A 20% Polkey deduction (chance she'd have been dismissed anyway), plus
• A 20% contributory conduct deduction for the employee's own behaviour

Net result: £6,930.90 from what could have been a much larger award. Procedural fairness doesn't insulate you from substantive findings about your conduct.

What the Code does NOT do

A few common misunderstandings:

• It does not require you to be given a copy of the Code. It's published online (acas.org.uk).
• It does not require legal representation at the hearing. Just the right to be accompanied by a colleague or trade union representative. Solicitors can sometimes attend by agreement but there's no general right.
• It does not apply to dismissals for redundancy alone, ill health, or non-renewal of fixed-term contracts. These have their own procedural requirements but they're not under the ACAS Code. (The Code's introduction says so explicitly.)
• It is not a complete statement of the law on fair process. The general "range of reasonable responses" test under s.98(4) ERA 1996 still applies on top.
• Following the Code does not guarantee a fair dismissal. It's the minimum, not the maximum.

How tribunals decide the uplift percentage

There is no fixed formula, but factors that push uplifts toward the maximum 25% include:

• Total or near-total failure to follow any step of the Code
• A larger or more experienced employer that should know better
• Repeated failures across the disciplinary, hearing, and appeal stages
• Failure to engage with the tribunal process itself (no ET3 response)
• The employer ignoring the employee's own attempts to raise the Code

Lower uplifts (10–15%) apply where some steps were followed but specific failures undermined the process — for example, an investigation was done but no proper hearing took place.

What to do if you think the Code was breached

1. Raise it during the process, in writing. If you're not given the evidence against you, or you're refused a companion, say so in writing before the hearing.
2. Appeal the decision within the employer's stated appeal window. Skipping the appeal can reduce a later tribunal award.
3. Contact ACAS for Early Conciliation within three months less one day of dismissal — mandatory before bringing a tribunal claim.
4. Document the timeline of every procedural failure. Tribunals award uplifts based on the specifics, not the headline.

See real cases

Cards below — six tribunal decisions where the ACAS uplift was a major part of the outcome.

Disclaimer

This page is general legal information, not legal advice. Speak to ACAS (free, 0300 123 1100), Citizens Advice, a trade union, or a qualified employment solicitor about your specific situation.