Dismissed for entering office out of hours: Teams chat sealed the case
A former employee was fairly dismissed after entering his workplace out of hours despite a final written warning. A Teams chat showing he planned to evade security was key evidence. The tribunal dismissed his unfair dismissal claim and refused the employer's costs application.
1 min read · Last updated 18 May 2026
Case details
- #teams-chat-evidence
- #final-written-warning
- #security-incident
- #costs-application-refused
Key facts
- The claimant was dismissed for entering the respondent's offices out of hours despite restrictions from a final written warning.
- A Teams chat showed the claimant discussing using an alternate entry to evade security.
- The respondent's disclosure included incident reports and witness statements detailing the seriousness of the incident.
- The tribunal found the claimant's claim for unfair dismissal had no merit and dismissed it.
- The respondent's application for costs was refused because the claim was not misconceived and required hearing all evidence.
Timeline
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Incident at offices
The claimant entered Marex's offices out of hours, triggering a security search and incident report.
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Witness statement exchange
The respondent provided witness statements and disclosure, including a Teams chat screenshot.
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Final merits hearing (day 1)
The tribunal heard evidence from both parties.
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Final merits hearing (day 2) and judgment
The tribunal dismissed the claimant's unfair dismissal claim.
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Respondent's costs application
The respondent applied for costs of £14,824.56, arguing the claim had no merit.
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Costs decision
Employment Judge Singh refused the costs application.
The legal issue
The tribunal had to decide whether the employer acted reasonably in dismissing the employee for entering the office out of hours in breach of a final written warning, and whether the employee's pursuit of the claim was unreasonable enough to justify a costs order.
The outcome
The tribunal dismissed the unfair dismissal claim, finding that the employer had a genuine belief in the misconduct and followed a fair process. The claim had no reasonable prospect of success.
- The employer's investigation was reasonable, relying on incident reports, witness statements, and a Teams chat where the employee discussed using an alternate entry to avoid security.
- The employee's final written warning made clear that any further breach could lead to dismissal.
- The employer's application for costs of £14,824.56 was refused because the claim was not misconceived from the outset and required a full hearing to assess all evidence.
Lessons & takeaways
- If you are on a final written warning, any further breach – even one you think is minor – can lead to dismissal.
- Digital evidence like Teams chats can be used against you in disciplinary proceedings, so be careful what you write.
- Pursuing an unfair dismissal claim that has little chance of success may not lead to a costs order, but it can still be a stressful and time-consuming process.
- Employers should ensure they conduct a thorough investigation, including gathering all relevant digital communications, before dismissing for misconduct.
A costly mistake caught on Teams
This case shows how a single incident – entering the office out of hours – can lead to dismissal when it follows a final written warning. The employee had been warned that any further misconduct could result in termination. Yet he chose to enter the building after hours, and a Teams chat revealed he had planned to use an alternate entrance to avoid security.
What the employer did right
Marex Financial conducted a proper investigation. They gathered incident reports, witness statements, and the Teams chat. They took the matter seriously, involving senior management and a security search. When they dismissed the employee, they had a genuine belief in the misconduct and acted reasonably. The tribunal agreed.
Why the costs application failed
After winning, Marex asked for costs of nearly £15,000, arguing the claim had no merit and should have been dropped after witness statements were exchanged. But the tribunal refused. Employment Judge Singh noted that the claim was not obviously misconceived from the start – it required a full hearing to assess all the evidence. This is a reminder that costs are exceptional in employment tribunals, even when the claim is weak.
What this means for similar cases
For employees, this case underscores the importance of adhering to final written warnings and being mindful of digital communications. For employers, it confirms that a thorough investigation and clear disciplinary process can withstand tribunal scrutiny. And for anyone considering a claim, it shows that even losing does not automatically mean paying the other side's costs.
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