The Serious Harm Test: What You Need to Know

What Is the Serious Harm Test?

Section 1(1) of the Defamation Act 2013 provides that a statement is not defamatory unless its publication has caused, or is likely to cause, serious harm to the reputation of the claimant. This single provision fundamentally changed the landscape of UK defamation law.

Before the 2013 Act came into force on 1 January 2014, claimants only needed to show that a statement had a tendency to lower them in the estimation of right-thinking members of society. There was no statutory requirement to demonstrate that the harm was "serious." The result was that trivial or technical claims could proceed, clogging the courts and chilling free expression.

Parliament introduced the serious harm test to strike a better balance between protecting reputation and safeguarding freedom of speech. The test raises the bar: a statement may be defamatory in the traditional sense, but unless the harm crosses the serious harm threshold, no claim can succeed.

The Old Law vs the New Law

Under the pre-2013 common law, courts applied a threshold of "real and substantial tort" — essentially asking whether the defamatory imputation was more than trivial. The case of Thornton v Telegraph Media Group Ltd [2010] introduced a requirement of "substantial" harm, but this was judge-made law rather than statute.

The Defamation Act 2013 replaced this common law threshold with a statutory one. Crucially, it raised the bar from "substantial" to "serious." This is not merely a semantic change. The Supreme Court confirmed in Lachaux that section 1 creates a higher hurdle that requires evidence, not just inference.

The Key Case: Lachaux v Independent Print Ltd [2019] UKSC 27

The landmark Supreme Court decision in Lachaux v Independent Print Ltd [2019] UKSC 27 settled the debate about how section 1 should be interpreted. The court unanimously held that section 1 requires claimants to prove as a fact that the publication of the defamatory statement has caused or is likely to cause serious harm to their reputation.

Lord Sumption, delivering the leading judgment, rejected the argument that serious harm could simply be inferred from the inherent tendency of the words. He held that section 1 was intended to change the common law, not merely codify it. The claimant must adduce evidence of serious harm — though the court acknowledged that such evidence can take many forms, including inferences drawn from the circumstances of publication.

How Courts Assess Serious Harm

Following Lachaux, courts consider a range of factors when determining whether the serious harm threshold is met. These include:

• The inherent gravity of the allegation — accusations of criminal conduct, dishonesty, or professional incompetence are more likely to cause serious harm than minor imputations.
• The extent of publication — a statement published to thousands online carries greater potential for harm than a comment made to a handful of people.
• The identifiability of the claimant — the statement must be understood by at least some publishees as referring to the claimant.
• Evidence of actual harm — witness statements from people who read the statement, evidence of lost business, job loss, or social exclusion.
• The claimant's pre-existing reputation — the court may consider whether the claimant's reputation was already damaged in the relevant area.
• Grapevine effect — the court can account for the tendency of defamatory statements to spread informally beyond their original publication.

Serious Harm for Businesses: Section 1(2)

Section 1(2) of the Defamation Act 2013 imposes an additional requirement on bodies that trade for profit. Such claimants must show that the defamatory statement has caused, or is likely to cause, serious financial loss. This is a higher threshold than for individuals, reflecting Parliament's concern that businesses should not use defamation law to silence legitimate criticism.

Proving serious financial loss typically requires evidence such as lost contracts, reduced revenue, customer cancellations, or quantifiable damage to goodwill. Speculative claims about potential future loss are unlikely to suffice. Businesses considering a defamation claim should begin gathering financial evidence at the earliest opportunity, including records that demonstrate a change in trading performance following publication.

Practical Implications for Claimants

If you are considering bringing a defamation claim, the serious harm test means you should:

• Preserve evidence of publication — take screenshots, note URLs, and record the date and extent of publication.
• Document the impact — keep a record of any consequences such as lost employment, damaged relationships, or emotional distress linked to the publication.
• Gather witness evidence — ask people who saw the statement and can speak to the harm it caused.
• Act promptly — the one-year limitation period is strict, and delay can undermine your case.
• Seek specialist legal advice — a defamation solicitor can assess the strength of your evidence against the serious harm threshold.

Practical Implications for Defendants

The serious harm test is a valuable tool for defendants. If you have been threatened with a defamation claim, or have received a pre-action letter, you should consider whether the claimant can realistically prove serious harm. Common grounds for challenging the threshold include:

• Limited publication — if the statement was seen by very few people, serious harm may be difficult to establish.
• Lack of evidence — the claimant must go beyond merely asserting harm; they must prove it with evidence.
• Pre-existing reputation — if the claimant's reputation was already poor in the relevant area, the marginal harm caused by the statement may not reach the serious harm threshold.
• Meaning dispute — the statement may not bear the defamatory meaning alleged by the claimant.

Common Misconceptions

Several misconceptions persist about the serious harm test. It is worth addressing the most common:

• "If a statement is defamatory, I automatically have a claim." — Not since 2014. You must also prove serious harm. A statement can be defamatory in the traditional sense but fail to meet the section 1 threshold.
• "Serious harm is obvious — the words speak for themselves." — Following Lachaux, you cannot rely on the words alone. You need supporting evidence.
• "Online publication always causes serious harm because the internet is permanent." — While widespread online publication can support a finding of serious harm, the court still requires evidence. A post seen by very few people may not meet the threshold, even if it remains technically accessible.
• "I need to prove financial loss." — Only if you are a body trading for profit. Individuals can establish serious harm through non-financial evidence.

Frequently Asked Questions