The Serious Harm Threshold in Australian Defamation Law

Serious harm is a threshold element a defamation plaintiff must now prove in every Australian jurisdiction except Western Australia: that the publication caused, or is likely to cause, serious harm to their reputation, decided by a judge rather than a jury.

This article addresses the serious harm element of the tort of defamation as it applies in New South Wales, Victoria, Queensland, South Australia, Tasmania, the ACT and, since 11 August 2025, the Northern Territory. It does not apply in Western Australia, which is covered separately below and in more detail on defamation law in Western Australia.

What Does the Serious Harm Element Require?

Serious harm is an element of the cause of action for defamation, meaning a plaintiff must establish it as part of proving their case, not merely respond to it as a defence. New South Wales' provision, representative of the wording used across the adopting jurisdictions, states it plainly:

"It is an element (the serious harm element) of a cause of action for defamation that the publication of defamatory matter about a person has caused, or is likely to cause, serious harm to the reputation of the person."

This sits on top of, not instead of, the traditional elements of defamation: that the matter was published, identified the plaintiff, and carried a defamatory meaning. A publication that meets those traditional elements but caused no serious reputational harm, a minor slight with no real consequences, will now fail at the threshold stage in every jurisdiction that has adopted this rule.

Who Decides Serious Harm, and When?

A judicial officer decides whether the serious harm element is established, not a jury, even in a jurisdiction where the rest of the case is tried by jury. The judge may determine the issue at any time before the trial commences or during it, on the application of either party or on their own initiative, and can make any order they consider appropriate, including dismissing the proceedings outright if satisfied the element is not made out. Where a party applies for an early determination, the judge is expected to decide it as soon as practicable before trial, unless satisfied there are special circumstances justifying postponement, weighing factors such as cost, the court's available resources, and how closely the serious harm question is bound up with other issues in the case. Critically, a judge may find the element is not established on the pleadings alone, without hearing further evidence, if satisfied the plaintiff's own pleaded particulars are insufficient to establish it. This gives defendants a genuine early exit where a claim is weak on its face.

Serious Financial Loss for Corporations

Where an excluded corporation has standing to sue (see the corporate-standing rule on the Australian defamation law hub), the serious harm test is recast in financial terms. Harm to a corporation's reputation is not serious harm unless the publication has caused, or is likely to cause, serious financial loss to the corporation. General reputational damage, without an accompanying financial consequence, does not satisfy the threshold for a corporate plaintiff.

Serious Harm by Jurisdiction

Two entries need a closer look than the table alone gives them. The Northern Territory's serious harm provision is numbered s 9A, not s 10A, because the Territory runs its own separately numbered Defamation Act 2006 rather than the "Defamation Act 2005" used elsewhere; do not assume NSW section numbers carry across to the NT. And Tasmania's commencement date is 12 November 2021, when the Defamation Amendment Act 2021 (Tas) No 16 received royal assent, not 1 July 2021 as it is frequently, and wrongly, reported alongside the other 1 July jurisdictions. See defamation law in Tasmania for why that four-month gap matters.

Why Western Australia Has No Serious Harm Threshold

Western Australia never enacted the Stage 1 reforms that introduced serious harm anywhere else in Australia. Its Defamation Act 2005 (WA) has no s 10A and no equivalent provision under any other number; the Act's causes-of-action division goes directly from the corporate-standing rule at s 9 to the deceased-persons rule at s 10, with nothing in between. A plaintiff in Western Australia is not required to prove serious harm at all, meaning WA effectively preserves the position that applied across the whole of Australia before 2021. This is one of the most consequential ways WA diverges from the rest of the country, discussed at length on defamation law in Western Australia.

Why Serious Harm Replaced the Old Triviality Defence

Serious harm and the old triviality defence addressed a similar underlying problem, insubstantial claims over trivial slights, but from opposite directions. Triviality let a defendant escape liability by proving the circumstances of publication were such that the plaintiff was unlikely to suffer harm, putting the burden of disproving harm on the defendant after the claim had already been brought. Serious harm instead makes the plaintiff prove the harm exists before the claim can proceed at all, front-loading the filtering function and shifting the burden onto the party bringing the claim. This is why every jurisdiction that adopted serious harm also repealed triviality in the same reform, and why Western Australia, having adopted neither change, is the only jurisdiction where triviality survives. See defamation defences in Australia for the full defences list, including where triviality still applies.

Serious Harm Does Not Change What Counts as Defamatory

It is worth being precise about what the serious harm threshold does and does not do. It does not change the underlying test for whether a publication is defamatory in the first place, that a matter must convey a meaning that would tend to lower the plaintiff in the estimation of ordinary reasonable members of the community, injure their reputation, or cause them to be shunned or avoided. Serious harm is an additional, separate hurdle layered on top of that existing test, not a replacement for it. A publication can satisfy the traditional defamatory-meaning test and still fail at the serious harm stage if the plaintiff cannot show the publication caused, or was likely to cause, serious harm to their reputation in fact.

The Practical Effect on Litigation Strategy

Because a judge can determine serious harm early, including on the pleadings alone, the threshold has changed how defamation litigation typically unfolds in the jurisdictions that have adopted it. A defendant with a genuine argument that any harm was minor now has a mechanism to test that argument before the expense of a full trial, rather than needing to wait until the substantive hearing to raise it as it would have been raised as triviality under the old law. This is one of the stated policy objectives behind the reform: filtering out low-value claims earlier in the process, before both parties have incurred the cost of preparing for a full trial on liability and damages.

This article provides general legal information about the serious harm element in Australian defamation law, verified 20 July 2026. It does not assess whether any particular publication meets or fails the threshold. For advice on your situation, consult a legal practitioner admitted in the relevant Australian state or territory.

Related reading: the Australian defamation law hub, concerns notices, defamation defences, and defamation law in Western Australia, the one jurisdiction where this threshold does not apply.