The Supreme Court of Queensland has recently determined that evidence from ChatGPT is irrelevant and inadmissible to determine the meaning of a lease.
The decision in Inspired Medical Pty Ltd v S Mohindra Pty Ltd [2026] QSC 78 reiterates that the interpretation of a contract (such as a lease) is a matter for the Court. The decision further adds to the rapidly growing jurisprudence regarding the use of generative AI in the legal profession.
Can ChatGPT give evidence?
One of the issues which fell for determination was the meaning of the term “medical centre” when used in a registered lease held by Inspired Medical Pty Ltd. The applicant (Inspired Medical Pty Ltd) sought to rely on evidence of answers given by questions that had been posed to ChatGPT, including:
“What is the ordinary meaning of the phrase ‘medical centre’?”
Justice Muir noted that the phrase ‘medical centre’ had no technical meaning, was not a term of art and was open to various interpretations.
Justice Muir acknowledged that large language models such as ChatGPT are emerging tools that may be useful for many tasks undertaken in legal practice and, interestingly, noted that overseas jurisdictions (including the United States) had recognised that generative AI had shown ‘some promise’ for judicial officers.
Her Honour, however, refused the evidence derived from ChatGPT, determining that it was irrelevant and inadmissible, for the following reasons:
- to the extent the Court needed to consider extrinsic materials (beyond the text of the lease), the Court was confined to recognised categories (e.g. circumstances known to both parties and the purpose and object of the transaction);1
- the questions posed to ChatGPT did not consider the text and factual matrix of the lease;
- using ChatGPT to ascertain the ordinary meaning of a term was compared, by analogy, to using a dictionary definition, which modern case law generally regards as unhelpful,2 especially for composite expressions like “medical centre”;
- the accuracy of the AI‑generated answers was unknown and, without the ability to check the underlying sources, the answers were unreliable; and
- the existing risks associated with the use of generative AI, together with concerns about its reliability, did not support its use by the Court – particularly having regard to practice guidelines released by the Court.3
Ultimately, it was found that the meaning of ‘medical centre’ was a question for the Court to determine on a proper construction of the Lease. Her Honour then undertook that exercise, applying orthodox principles of contractual interpretation. That is, the Court will ask what meaning the contract (in this case, a lease) would convey to a reasonable person having all the background knowledge which would reasonably have been available to the parties in their situation at the time of the contract.4 This requires consideration of the text of the contract, the surrounding circumstances then known to the parties and the purpose and object of the transaction.
Key takeaway
This case is a timely reminder about the limitations of generative AI in the context of litigation. ChatGPT is neither expert evidence nor a shortcut to the established principles of construction of a lease, or indeed a substitute for evidentiary material.
Despite its undeniable utility in efficiently performing tasks which once may have occupied many hours of a lawyer’s day, the use of generative AI will not, and cannot, supplant common law judicial reasoning. Generative AI cannot, at least for now, be a substitute for the professional expertise and objectivity that the administration of justice requires.
- Toll (FGCT) Pty Ltd v Alphapharm Pty Ltd (2004) 219 CLR 165 [40]. ↩︎
- Century Mining Pty Limited v The Commissioner of State Revenue [2024] QSC 143 at [72]; with reference to Built Qld Pty Ltd v Pro-Invest Australian Hospitality Opportunity (ST) Pty Ltd (2022) 13 QR 148 at [30]; SDA v Corporation of the Synod of the Diocese at Rockhampton (2021) 8 QR 440, 449 at [10] and [11]. ↩︎
- The Use of Generative AI Guidelines for Judicial Officers dated 15 September 2025, issued by the Supreme Court of Queensland; A Guide to the Use of Artificial Intelligence issued on 20 February 2026 by the High Court of Australia. ↩︎
- Inspired Medical Pty Ltd v S Mohindra Pty Ltd [2026] QSC 78, at [63]; Maggbury Pty Ltd v Hafele Australia Pty Ltd (2001) 210 CLR 181, 188 at [11] per Gleeson CJ, Gummow and Hayne JJ with reference to Lord Hoffman in Investors Compensation Scheme Ltd v West Bromwich Building Society [1998] 1 WLR 896 at [912]. ↩︎