Nippon Life v. OpenAI: ChatGPT Accused of Practicing Law

A landmark lawsuit filed in March 2026 is forcing the legal industry to confront a question it has long avoided: when an AI tool drafts your court filings, argues your case, and tells you to fire your attorney — is it practising law?

Key facts

• Nippon Life Insurance Company of America filed suit against OpenAI in the U.S. District Court for the Northern District of Illinois, Case No. 1:26-cv-02448, in March 2026.
• The claimant submitted more than 60 ChatGPT-assisted documents across two court cases — one citing a nonexistent case — and Nippon Life incurred ~$300,000 defending a matter settled in January 2024.
• Nippon Life seeks $10M in punitive damages, a declaratory judgment that OpenAI violated Illinois law, and a permanent injunction barring OpenAI from practising law in the state.

The Case at a Glance

On 5 March 2026, Nippon Life Insurance Company of America filed suit against OpenAI in the U.S. District Court for the Northern District of Illinois (Case No. 1:26-cv-02448). The dispute stems from a long-term disability claim that the two parties settled in January 2024 — with the claimant signing a full release and the case being dismissed with prejudice.

A year later, the claimant had second thoughts. Her own attorney told her the release was enforceable and the matter was closed. Rather than accept that advice, she uploaded the attorney's response to ChatGPT and asked whether she was being misled. ChatGPT told her she was.

What followed was extraordinary. Using ChatGPT, the claimant drafted motions, generated legal arguments, conducted legal research, and submitted more than 60 documents across two court cases — one of which cited a case that does not exist and appears only in ChatGPT's output. By the time Nippon Life filed this new lawsuit, the insurer had incurred approximately $300,000 defending a case it had already settled.

Three Core Claims

Nippon Life's lawsuit is built on three distinct legal theories:

• Tortious interference with a contract — OpenAI's tool actively helped disrupt an already-settled legal agreement
• Abuse of process — ChatGPT facilitated the filing of baseless court documents in a matter already disposed of
• Unlicensed practice of law under Illinois statute — ChatGPT provided legal advice, drafted legal strategy, and engaged in what Nippon Life characterises as the practice of law without a licence in Illinois

Nippon Life is seeking $10 million in punitive damages, a declaratory judgment that OpenAI violated Illinois law, and a permanent injunction barring OpenAI from practising law in the state.

Stanford Law School has characterised the case as fundamentally a product liability matter — arguing that OpenAI designed a product it knew could cross the line between information retrieval and legal counsel.

Why This Case Matters Beyond the Headlines

What Happens When Consumers Trust ChatGPT for Legal Advice

Nippon Life is the extreme version. But the claimant in that case is not an outlier — she is the visible end of a pattern courts are now seeing every week. Ordinary people, with no law degree and no lawyer, ask ChatGPT what to do, take its answer at face value, and walk into a courtroom holding case law that was never decided by any judge. The model does not know the difference. It produces a confident, well-formatted citation whether or not the case exists. Here are three documented examples from real courts, none of them lawyers, all of them people who trusted a chatbot the way you would trust a lawyer.

Harber v HMRC: nine cases cited, nine invented

Felicity Harber, a litigant in person in the UK, appealed a £3,265 tax penalty before the First-tier Tribunal (Tax Chamber). To support her argument she cited nine prior decisions. All nine were fabricated by a generative AI system. The judge, Anne Redston, accepted that Harber genuinely had not realised the cases were the product of hallucination — she was not trying to deceive anyone. The tells were there if you knew to look: American spelling like "favor" in a UK tax case, identical phrasing repeated across supposedly unrelated judgments, and authorities that addressed late filing when her actual penalty was for failure to notify. Her appeal was rejected. The lesson is not that she lied. The lesson is that a non-lawyer cannot tell a real citation from an invented one, and ChatGPT will hand them both with equal confidence.

Jack Owoc: pro se against Monster Energy, eleven fake citations

Jack Owoc, founder of Bang Energy, represented himself in a Florida federal court against Monster Energy in a dispute over a large judgment. His motion to dismiss, and the reply that followed, together contained eleven citations to cases that do not exist — six in the motion, five in the reply. Monster Energy's lawyers flagged them as a "series of cases that do not appear to exist." Owoc told the court he and his wife are raising six children and cannot afford an attorney, so he had used AI. The magistrate judge ordered him to complete community service, required him to disclose any AI use in every future filing, and the court weighed a motion to bar him from filing anything further without permission. He was not a lawyer cutting corners. He was a self-represented litigant who could not afford one and reached for the free tool everyone talks about.

The ProHealth trade mark appeal: ChatGPT in an IP case

In a UK Intellectual Property Office appeal over the trade mark "ProHealth," a litigant in person, Dr Mustapha Soufian, drafted his case with help from ChatGPT. The appointed person hearing the appeal, Phillip Johnson, found errors throughout the citations and the skeleton argument. Johnson went further than the individual ruling: he recommended that the trade mark registrar issue clear warnings to all litigants about the risks of using AI, because self-represented parties keep arriving with the same broken homework. "It is important that all litigants before the registrar... are made aware of the risks of using artificial intelligence," he wrote.

Tie this back to the unauthorised-practice thesis. In each case, ChatGPT did the thing only a licensed lawyer is supposed to do: it told a non-lawyer what the law was and how to argue it. It just did it wrong, with no licence, no accountability, no malpractice insurance, and no bar association that can sanction it. When a real lawyer hands a client a fake citation, there is a name on the filing and a regulator who can act. When ChatGPT does it, the consumer absorbs the entire consequence. That asymmetry — the model practises law in everything but name, while the user carries all the liability — is the heart of why Nippon Life v. OpenAI matters far beyond one settled insurance claim.

• AI conversations are not privileged
• 1,313 court cases involving AI hallucinations
• Harber v HMRC: litigant put fake AI cases before the tribunal (Legal Futures)
• Bang Energy founder faces filing ban over fake AI cases (Law360 Pulse)
• Tribunal warns against AI use after fake cases in trade mark appeal (Law Gazette)

The lawsuit highlights a critical flaw in the narrative that AI is "just a tool." ChatGPT did not passively answer a question here; it formulated litigation strategy, drafted procedural documents, cited non-existent case law, and — according to the complaint — actively advised the claimant to override the counsel of a licensed attorney.

ChatGPT is not an attorney. It has not been licensed to practice law in the State of Illinois or any other jurisdiction in the United States.

OpenAI is expected to argue that users — not the company — bear responsibility for how they use the tool, and that providing information is not the same as practising law. But as Stanford Law notes, the complaint is carefully constructed to counter this by documenting ChatGPT's active participation in legal strategy, not merely passive information delivery.

What This Means for the Legal Profession

For practising lawyers and legal professionals, Nippon Life v. OpenAI is not merely an interesting story about a tech company in court. It is a warning about what happens when powerful general-purpose AI tools operate without boundaries in the legal space.

The hallucinated case citation alone — submitted to a federal court — illustrates the profound risks of using unspecialised AI for legal tasks.

This case should accelerate the conversation about which AI tools are appropriate for legal practice, who bears accountability when AI output causes harm, and why the legal profession demands purpose-built solutions held to professional standards — not consumer chatbots that have never sat a bar exam, and cannot be sanctioned by one.

• AI conversations are not privileged
• 1,313 court cases involving AI hallucinations
• the public database tracking fake AI citations
• Explore HAQQ Legal AI — Purpose-Built for Law
• Compare HAQQ vs Generic AI Tools
• Read About AI Ethics in Legal Practice

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