I think someone is lying in a disciplinary hearing

12th October 2026

Most managers walk into a disciplinary hearing believing the job is to find out what really happened. It is reasonable, and wrong. By the time an employee is sitting across the table giving an account you do not believe, the question has quietly changed. You are no longer establishing truth. You are deciding what you can reasonably conclude, and showing how you got there. That distinction is the whole of this article.

You do not have to prove it

The standard is not the one you see on television. You are not a court and you do not need to be sure. If a tribunal ever examines this, the questions are what your reason for the decision was, and whether you acted reasonably in treating it as a sufficient reason for what you did. That is how section 98 of the Employment Rights Act 1996 frames it, and it asks about your conduct as the employer, not about whether a judge would have made the same finding of fact.

The working version most employment lawyers use runs like this. You need a genuine belief that the employee did the thing, reasonable grounds for that belief, and a reasonable investigation behind it. That formulation comes from decided cases rather than statute or Acas guidance, so treat it as the shape of the test rather than words you can point at in a book.

Two things follow, and they cut in opposite directions. “I cannot be completely certain” is not a reason to do nothing. “I just know they are lying” is not reasonable grounds for anything.

Test the account, not the person

Most managers think they can tell. It is not a method you can show anybody. Confidence, eye contact, tears and indignation are all things honest people do and dishonest people also do, and a manager who has decided somebody seems shifty has usually decided something about personality, not evidence. Acas tells an investigator to record which facts were established and which were not, which is useful precisely because it has nothing to do with how anybody came across in the room.

So work on the account. Four questions do most of the work.

Is it internally consistent? Not word for word, because real memory is messy and a story that matches a previous version perfectly is its own small warning sign. You are looking for a change on the point that matters, especially one that arrives only after the employee learns what you know.

Does it survive contact with something nobody could adjust afterwards? Till records, door entry logs, delivery timestamps, rota changes, the sent folder. One objective record beats an hour of questions.

Is any part of it confirmed by somebody with nothing to gain? Acas says an investigator need not speak to every witness, but should where there are significant differences in what the witnesses say. A direct conflict of accounts is exactly that.

Does it explain the thing it has to explain? Much disciplinary evidence is not a lie so much as an account that leaves the central fact untouched.

Adjourn. Almost everyone skips this

Here is the move that goes wrong most often. An employee produces a new explanation in the hearing, the manager does not believe it, and decides against them in the same meeting. That is the decision a tribunal takes apart, not because the conclusion was wrong but because nobody checked.

If the account is new to you, you cannot sensibly assess it in the room. Adjourn, test the new claim against whatever can verify it, and reconvene. Acas’s page on the disciplinary hearing is mostly about who attends and making sure somebody takes notes, so you will not find this spelled out there, but a hearing that ends with “we are going to pause and look into that” is stronger every time. If the explanation checks out, you have been saved from a bad dismissal. If not, you now have reasonable grounds instead of a feeling.

Give the employee the material you relied on as well. The Acas Code of Practice says at paragraph 9 that it is normally appropriate to provide copies of any written evidence, which may include witness statements. You cannot test an account while keeping half of it in your folder.

If the lie itself is the problem, it has to be an allegation

This is where small employers get caught. A manager invites somebody to a hearing about one thing, decides during it that they are being dishonest, and dismisses them for the dishonesty. The employee never had notice of that allegation and no chance to answer it, which paragraphs 9 and 12 of the Code both require.

You have two honest routes and you should pick one deliberately.

Treat the account as going to credibility on the original allegation. You are not disciplining anybody for lying. You are explaining why you preferred one version of events when deciding the original charge. Usually this is the right route.

Or put dishonesty during the process as a fresh allegation. That means a new invitation letter setting out what you say was untrue and the evidence for it, a reasonable period to prepare, and the statutory right to be accompanied again. It is slower, and the only safe way to sanction somebody for the lying rather than the original conduct.

Getting it wrong also makes any award bigger. A tribunal can increase it by up to 25 per cent where an employer unreasonably failed to follow the Code, under section 207A of the Trade Union and Labour Relations (Consolidation) Act 1992.

Write down why you believed one account over the other

Your outcome letter should say which facts you found established, which you did not, and what made you prefer one account. Not “the employee was not credible”. Something closer to “your explanation that you were on a break at 14:10 does not fit the till records, which show two transactions on your login at 14:08 and 14:14, and you did not mention the break until after you were shown those records.”

That does three jobs. It gives reasons, it shows you tested the account rather than judged the person, and it is readable by somebody who was not in the room. The disciplinary outcome letter template has the structure. Then offer an appeal, and have somebody else hear it if you possibly can, since Acas recommends a different person at each stage where that is possible.

Your file now has to outlive your memory of it

Since 1st October 2026 the time limit for most tribunal claims has been six months minus one day rather than three months minus one day. The transitional rule matters: the longer limit applies only where the relevant date falls on or after 1st October 2026, and for unfair dismissal the relevant date is the day the employment ended. A dismissal you carry out now runs on the new clock. Something that happened in September still runs on the old one.

Early conciliation then pauses that clock, so a claim arising from a hearing this month could reach you well past the six month mark, with a hearing after that. Assume your notes and your evidence need to be intelligible to a stranger most of a year from now. Write them for that reader.

There is also less margin coming. From 1st January 2027 the qualifying period for ordinary unfair dismissal drops from two years to six months, which pulls far more of these decisions into claim territory than most owners realise. That is covered in unfair dismissal at six months.

What to do on Monday

If you are mid process and you do not believe what you have just heard, adjourn. Write down the specific points you doubt and what would verify or disprove each one, and go and check those things. Then decide, and say plainly in the letter why. You are allowed to conclude that somebody is not telling you the truth. You are not allowed to conclude it without looking. And if they resign before you get there, the process does not simply disappear: see resigning in the middle of a disciplinary.

Tarn.hr provides HR guidance based on UK employment law and Acas codes of practice. It does not constitute legal advice and should not be relied upon as such. Employment law is complex and turns on the facts of each case. For any situation involving significant legal risk, potential tribunal claims, or matters of particular sensitivity, you should seek advice from a qualified employment solicitor. Tarn.hr is not responsible for any decisions made on the basis of its guidance.