Australian Defamation Law: Serious Harm, Concerns Notices and Deadlines

Australian defamation law is set by each state and territory, but the laws are based on shared model provisions, so the core rules are broadly uniform across the country. In most jurisdictions you must show that a published statement about you has caused, or is likely to cause, serious harm to your reputation, send a concerns notice before suing, and start proceedings within one year of publication, though a court can extend that in some cases.

This guide explains the general principles and the practical steps that sit alongside a claim. It is general information, not legal advice. The reforms of recent years have not been adopted at the same time everywhere, so speak to a solicitor in your state or territory who handles defamation before you act.

Uniform laws, state by state

Before the mid-2000s, defamation law differed significantly between the states. The states and territories then agreed on Model Defamation Provisions and passed near-identical Defamation Acts. That gave Australia a largely uniform system, alongside the common law.

Since then, the model provisions have been reformed in stages. Stage 1 amendments, which included the serious harm element and a mandatory concerns notice process, took effect in most jurisdictions from 2021, with others following later. Stage 2 amendments on digital intermediaries began in some states in 2024. Because each parliament passes its own version, a solicitor will check exactly which version applies to your publication date and place.

What you need to show

To bring a defamation claim in Australia, you generally need to show that:

1. The material was published to at least one person other than you.
2. It identified you, by name or in a way people who know you would recognize.
3. It carried a defamatory meaning, sometimes called an imputation, that would lower you in the estimation of ordinary reasonable people.
4. It caused, or is likely to cause, serious harm to your reputation, in jurisdictions that have adopted the Stage 1 reforms.

As in the UK and Canada, you don’t have to prove falsity at the outset. The defendant has to prove truth if they rely on it. Our guide to libel vs slander covers the traditional distinction, though Australia’s uniform laws largely abolished it, so spoken and written statements are treated the same way.

Who can sue

Most companies can’t sue for defamation in Australia. Under the uniform laws, only certain corporations can, generally not-for-profit organizations and small businesses with fewer than 10 employees that aren’t related to another corporation. Directors and owners can still sue personally if a statement defames them as individuals. Larger businesses usually look to other routes, such as injurious falsehood or consumer law.

The serious harm element

The Stage 1 reforms added a requirement that the publication has caused, or is likely to cause, serious harm to the person’s reputation. For an excluded corporation that is allowed to sue, the harm must involve serious financial loss.

The judge decides serious harm, usually early in the case. Evidence that tends to help includes:

• how many people saw the publication and who they were,
• the seriousness of what was alleged, such as a crime, dishonesty or professional misconduct,
• messages or conduct showing people believed it and treated you differently,
• lost clients, contracts, job offers or income.

The aim of the change was to stop minor disputes, such as neighborhood arguments on social media, from turning into full defamation trials.

Concerns notices

In jurisdictions that have adopted the Stage 1 reforms, you can’t start defamation proceedings until you’ve given the publisher a concerns notice and waited for a set period for them to respond, unless the court gives leave.

A concerns notice must be in writing and generally has to identify the matter complained of, the defamatory imputations you say it carries, and the harm you say it has caused or is likely to cause. The publisher can respond with an offer to make amends, which might include a correction, an apology, removal and costs. If a reasonable offer is refused, that can help the publisher’s defense later.

Many disputes end at this stage. A clear, well-drafted notice from a solicitor often achieves removal or a correction without any court proceedings.

The main defenses

Defense	What it means in general terms
Justification (truth)	The defendant proves the defamatory imputations are substantially true.
Contextual truth	Other true imputations in the same publication were so serious that the ones complained of did no further harm.
Honest opinion	The material was an opinion rather than a statement of fact, on a matter of public interest, based on proper material.
Public interest	Added by the Stage 1 reforms: the matter concerned an issue of public interest and the defendant reasonably believed publishing it was in the public interest.
Privilege and fair reports	Statements in court and parliament, and fair reports of public proceedings, are protected.
Innocent dissemination	A distributor who didn’t know, and shouldn’t reasonably have known, the material was defamatory may be protected.

As in other countries, opinion-based criticism is generally protected. Our guide on defamation vs opinion explains how to tell the difference.

Time limits

The limitation period for defamation in Australia is generally one year from publication. A court can extend it, up to a maximum of three years, if it’s satisfied it wasn’t reasonable in the circumstances to start proceedings within one year. Several jurisdictions have also adopted a single publication rule, so the period generally runs from the first publication of the same material by the same publisher.

Because the concerns notice process takes time, the practical window is shorter than a year. If you’re considering a claim, contact a solicitor early.

Online platforms and digital intermediaries

Online publication has been a major issue in Australia. The High Court decided in 2021 that media outlets could be treated as publishers of comments posted by third parties on their public Facebook pages. That decision increased concern about who is responsible for online comments.

The Stage 2 reforms respond to this. In the states that have adopted them, starting with New South Wales and the ACT in 2024, the changes include, in general terms:

• exemptions from liability for some intermediaries that play only a passive role, such as certain search engine results, caching and messaging services,
• a defense for digital intermediaries, including people who run forums or social media pages, if they have an easy way for complaints to be made and they take reasonable steps, such as removing content, within a set time after a complaint,
• powers for courts to order non-party platforms to remove or block access to defamatory material.

Adoption has varied by jurisdiction, so check with a solicitor how these rules apply where you are. Separately, Australia’s eSafety Commissioner can act on serious online abuse under the Online Safety Act, which is a different route from defamation and can be faster where content is menacing or harassing.

A worked example

This is an illustrative scenario, not a real client.

A small accounting practice in Brisbane with six staff finds a post in a local business group claiming the principal “has been stealing from client trust accounts.” There has never been any complaint or investigation. Two clients ask to move their files.

The principal saves the post and comments with dates and links and makes a note of the two clients’ messages. Her solicitor advises that the principal can sue personally, and that the practice itself may qualify because it has fewer than 10 employees. The solicitor sends a concerns notice to the author setting out the imputation of dishonesty and the harm, and separately uses the group’s complaint process to ask the page administrator to remove the post.

The administrator removes the post, and the author responds with an offer to make amends, including a published apology in the same group. The principal accepts, and then updates her firm’s website and profiles so that searches show accurate information first.

Common mistakes

• Skipping the concerns notice. In most jurisdictions you can’t sue without one.
• Assuming a company can sue. Most corporations can’t, though individuals behind them may.
• Letting the year run out while hoping the post disappears.
• Relying on US advice, which is built on different rules about falsity, fault and platform immunity.
• Responding with counter-accusations, which can expose you to a claim of your own.

Getting help

For legal advice, look for a solicitor who handles defamation or media law in your state or territory. Each state and territory law society runs a referral service that can suggest solicitors, and community legal centres and state legal aid commissions can help you understand your options, though legal aid is rarely granted for defamation claims.

For the reputational side, our crisis management service helps when a damaging statement is spreading, and our content removal service works on legitimate routes such as platform policies and publisher requests. If you want to compare approaches, our guides to UK defamation law and Singapore defamation law cover related systems.

Frequently asked questions

Is defamation law the same in every Australian state?

Mostly. Each state and territory has its own Defamation Act based on shared model provisions, so the core rules are similar. Recent reforms have been adopted at different times, so some details depend on where and when the statement was published.

What is a concerns notice?

It’s a written notice to the publisher that identifies the material, the defamatory meanings you complain of, and the harm caused. In most jurisdictions you must send one and wait for a response period before suing. A solicitor should draft it.

How long do I have to sue for defamation in Australia?

Generally one year from publication. A court can extend it up to three years if it wasn’t reasonable to sue sooner, but you shouldn’t count on that. Speak to a solicitor early, because the concerns notice process takes time.

Can a business sue for defamation in Australia?

Only certain corporations, generally not-for-profits and small businesses with fewer than 10 employees that aren’t part of a larger group. Owners and directors can sue personally if they’re defamed as individuals. Other businesses may have options such as injurious falsehood.