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Defamation Act 2013 Explained: What Counts as Libel in the UK?

Published 9 July 2026

In November 2012, Sally Bercow tweeted two words: "Why is Lord McAlpine trending? *innocent face*." The tweet came during a wave of speculation about a BBC Newsnight report that did not name anyone but left viewers with enough clues to guess. Lord McAlpine sued. He won. Bercow settled — reportedly for a substantial sum. Two words. One tweet. A life-changing financial liability.

Defamation — libel and slander — is the area of law where words cost money, not liberty. You cannot be imprisoned for defamation. But you can be sued for damages that bankrupt you. And under the Defamation Act 2013, the bar for bringing a claim is higher than it used to be — deliberately so. This guide explains what counts as libel, what the defences are, and why the 2013 Act matters.

Disclaimer: General information, not legal advice. If you have received a letter before action for defamation, speak to a solicitor immediately. The one-year limitation period is strict.

Jurisdiction: England and Wales. Scotland has separate defamation law. Northern Ireland has distinct provisions.

Defamation Act 2013: The Framework CIVIL — NOT CRIMINAL — Damages only, no imprisonment SERIOUS HARM s.1 — Claimant must prove "serious harm" to reputation DEFENCES Truth (s.2) — complete defence Honest opinion (s.3) TIME LIMIT One year from publication Every retweet/share resets it "A statement is not defamatory unless its publication has caused or is likely to cause serious harm to reputation" — s.1(1) Lachaux v Independent Print [2019] UKSC 27: serious harm must be proved by EVIDENCE, not inference Key cases: McAlpine v Bercow [2013] (settled); Stocker v Stocker [2019] (ordinary reader); Monroe v Hopkins [2017] (won) Public interest defence (s.4). Website operators defence (s.5). Peer-reviewed scientific journals (s.6).
The Defamation Act 2013 framework: serious harm threshold, three key defences, and a strict one-year limitation period.

The Serious Harm Threshold: Lachaux Changed Everything

Before 2013, reputation damage was largely presumed — if a statement was defamatory, harm was assumed. Section 1 of the Defamation Act 2013 changed that. A statement is not defamatory unless it has caused — or is likely to cause — serious harm to the claimant's reputation. "Serious" does real work. Trivial harm, minor embarrassment, or hurt feelings are not enough.

In Lachaux v Independent Print [2019] UKSC 27, the Supreme Court made clear that serious harm must be proved by evidence, not inferred from the nature of the statement. A newspaper published articles falsely accusing a man of child abuse abroad. The Supreme Court held that while the allegations were grave, the claimant still had to produce evidence of actual reputational damage — and on the facts, he succeeded. The case established that serious harm is a meaningful threshold, not a formality.

The Defences: What Protects You

If you are sued for libel, four statutory defences — all in the 2013 Act — are your main arguments:

Truth (s.2): If the statement is substantially true, it is not defamatory — even if it caused serious harm. The defendant must prove truth, not the claimant. This is the strongest defence. If the core allegation is true, minor inaccuracies do not defeat it — the Act requires that the imputation is "substantially true," not perfectly accurate.

Honest Opinion (s.3): A statement of opinion — not fact — based on facts that existed at the time, on a matter of public interest. The opinion must be one that an honest person could have held. This protects reviews, commentary, and genuine expressions of view — even harsh ones.

Public Interest (s.4): Publication on a matter of public interest where the publisher reasonably believed publication was in the public interest. This is the broadest defence and the one most commonly relied on by journalists and publishers. It replaced the old common-law "Reynolds defence" with a more flexible statutory test.

Website Operators (s.5): A defence for website operators who did not post the defamatory statement themselves — provided they comply with procedures for identifying the poster. This protects platforms hosting user-generated content.

Before and After: How the 2013 Act Changed Libel Law BEFORE 2013 Harm presumed from defamatory statement No statutory public interest defence London known as "libel capital of the world" AFTER 2013 Serious harm must be proved by evidence Truth, honest opinion, public interest defences Higher bar, fewer claims, more free-expression protection One-year limitation period from publication. Every retweet or share resets the clock — republication = new cause of action. CRIMINAL vs CIVIL: Defamation is CIVIL ONLY. s.127 Comms Act = criminal. MCA 1988 = criminal. Damages never = prison. Sources: Defamation Act 2013; Lachaux v Independent Print [2019] UKSC 27
How the 2013 Act changed libel law: higher bar, statutory defences, and a clear civil/criminal distinction.

The Criminal/Civil Distinction — And Why It Matters

This is the most important thing to understand about defamation: it is civil, not criminal. You cannot be arrested, charged, prosecuted, or imprisoned for libel. The worst that can happen is a judgment for damages. The police have no role. The CPS has no role. It is a dispute between private parties, resolved in the civil courts.

Compare the criminal offences that cover similar territory. Communications Act 2003, s.127 — grossly offensive or menacing messages. Maximum: 6 months' imprisonment. Malicious Communications Act 1988 — messages sent with purpose to cause distress. Maximum: 2 years. A false statement about someone posted online could engage all three: defamation (civil, damages), s.127 (criminal, 6 months), and the MCA (criminal, 2 years). The defamation claim is the civil route; s.127 and the MCA are the criminal routes. They operate in completely different legal systems with different standards of proof, different procedures, and different consequences.

The One-Year Limitation Period

An action for defamation must be brought within one year from the date of publication (s.8). The court has discretion to extend this, but only in exceptional circumstances. This is strict — miss the deadline and the claim is time-barred. Critically, every republication — every retweet, every share, every new post repeating the same allegation — is a new publication with its own one-year limitation period. The clock resets every time the statement is republished.

Practical Takeaways: Reducing Your Defamation Risk 1. Is it true? Truth = complete defence 2. Is it opinion? Honest opinion = defence 3. Does it cause serious harm? Trivial harm = no claim 4. Do not retweet libel Sharing = republication If you receive a letter before action — do not ignore it. Speak to a solicitor. The clock is running. UK Content Comply analyses content against 13 UK speech law frameworks. See resources page.
Four questions to ask before posting — and what to do if you receive a letter before action.

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