Defamation by Former Employees: What Businesses Can Do

When an employee leaves on bad terms, the damage does not always end at the exit interview. Former employees who take to social media, contact your clients directly, or give interviews to journalists making false allegations about your business can cause serious — sometimes devastating — reputational harm. UK defamation law provides businesses with powerful remedies, often combined with other legal tools.

How Former Employees Defame Businesses

The most common scenarios involving defamation by former employees include:

• Social media posts — false allegations about workplace conditions, criminal conduct, financial fraud, or illegal practices posted to LinkedIn, Twitter/X, Facebook, or TikTok.
• Glassdoor reviews — anonymous reviews containing fabricated serious allegations, particularly those that go beyond subjective opinion (which is not actionable) to false statements of fact.
• Contacting clients or suppliers — a former employee directly messaging your customers or business partners with false allegations about your products, services, or professional conduct.
• Media contact — providing false information to journalists, bloggers, or industry publications, which then publish it to a wide audience.
• WhatsApp and group chats — sending false allegations to industry WhatsApp groups, professional forums, or closed communities where the audience is specifically relevant to your business.

When Does It Become Defamatory?

Not everything a disgruntled former employee says is actionable. To bring a defamation claim, the statement must:

• Be a statement of fact (not merely opinion)
• Be false
• Have caused or be likely to cause serious harm to the reputation of the business — which for companies means serious financial loss or the likelihood of it (s.1(2) Defamation Act 2013)
• Have been published to at least one person other than the claimant

Statements of opinion — "they treated me terribly," "the culture was toxic" — are generally protected by the honest opinion defence. However, false factual allegations — "they defrauded clients," "they fired me for raising a safety issue," "they operate illegally" — can be actionable, particularly where the former employee has embellished or invented specifics.

Serious harm for a business means demonstrating that the allegations caused or are likely to cause serious financial loss. Evidence might include lost contracts, cancelled orders, departing clients, or damaged supplier relationships.

Defamation vs. Breach of Contract

Former employees are often subject to post-termination restrictive covenants in their employment contracts, which may include confidentiality obligations, non-disparagement clauses, or non-solicitation provisions. Where a former employee breaches such a clause, you may have a contractual remedy in addition to — or instead of — a defamation claim.

Defamation and breach of contract claims can run in parallel. The advantage of a contractual claim is that you do not need to prove serious harm — you only need to show a breach of the agreed term. However, courts will only enforce reasonable restrictive covenants, and excessively broad non-disparagement clauses may not be enforceable.

A specialist solicitor will assess which cause of action gives you the strongest position, which remedies are available, and which route is most likely to achieve your objectives — usually a combination of content removal, injunction, apology, and compensation.

Emergency Injunctions

Where defamatory content is spreading rapidly — particularly if a former employee is actively contacting clients or the content is going viral — an emergency interim injunction may be available to stop further publication immediately. An application can sometimes be made without notice to the defendant (a without-notice or ex parte application) where giving notice would defeat the purpose of the application.

The court applies the American Cyanamid test: is there a serious question to be tried, and does the balance of convenience favour granting or refusing the injunction? In defamation cases, courts are generally cautious about pre-publication injunctions (because of Article 10 freedom of expression), but where content has already been published and is causing active, measurable harm, interim injunctive relief is more readily granted.

GDPR as a Parallel Lever

Where a former employee has disclosed confidential information about your business, clients, or employees as part of their campaign, UK GDPR may give you an additional remedy. If personal data has been unlawfully disclosed, you may be able to bring a claim under the Data Protection Act 2018, seek an injunction, or report the breach to the Information Commissioner's Office (ICO).

A Norwich Pharmacal Order can be used to unmask anonymous reviewers on platforms such as Glassdoor where the former employee has posted under a pseudonym, allowing you to identify who made the allegation before bringing a defamation claim.

Settlement Strategy

Most defamation disputes involving former employees resolve without litigation. A well-drafted legal letter from a specialist solicitor — making clear that the allegations are false, that evidence is being gathered, and that proceedings will follow if the content is not removed and an apology provided — is often sufficient to prompt immediate compliance.

Where the former employee is motivated by an underlying employment grievance (unfair dismissal, discrimination, unpaid wages), a global settlement resolving both the employment and defamation disputes simultaneously is often the most efficient solution. This requires coordination between employment law and defamation law expertise.

Related reading: Defamation injunctions: how to stop publication | Defamation claims for businesses | How defamation disputes settle out of court