On 26 March 2026, the Court of Appeal of Ireland handed down judgment in Guerin v O'Doherty [2026] IECA 48, in which the President of the Court, Ms Justice Costello, set out guidelines on the use of artificial intelligence by parties in litigation. The judgment addresses the procedural obligations arising when AI tools assist in preparing written submissions and marks the first time an Irish appellate court has issued structured AI-use guidelines binding on parties appearing before it. The decision is final and published; it carries immediate effect for all parties to proceedings before the Court of Appeal.
The controlling authority is the Court of Appeal's inherent jurisdiction to regulate its own procedure, exercised through the judgment delivered on 26 March 2026. At paragraphs 72 to 75, Ms Justice Costello set out five conditions: (i) parties may use AI to assist with research, provided they do not mislead the court; (ii) any party that uses AI must expressly inform both the opposing party and the court of that use; (iii) a self-represented party using AI retains full responsibility for the final written or oral work produced; (iv) any AI-generated authority must be independently verified by the party before it is relied upon; and (v) no authority may be cited unless the party has verified it is a genuine judgment from the cited court. The court found that the defendant had included AI-generated references in her written submissions without verifying their existence or accuracy.
Lawyers and self-represented litigants appearing in the Irish Court of Appeal must now disclose AI use in written submissions, verify every case citation they intend to rely on, and accept personal responsibility for the content of AI-assisted work product. Failure to comply exposes a party to adverse costs consequences and, where false authorities are submitted knowingly, to potential contempt or strike-out of the affected submissions. Legal technology vendors marketing AI drafting tools to Irish practitioners must factor this disclosure requirement into their client-facing guidance and terms of service.
The court expressly distinguished legitimate research assistance, which the guidelines permit, from the uncritical reproduction of AI outputs, including fabricated case citations, which it treats as a breach of the duty not to mislead the court. The judgment does not prescribe a specific disclosure form; the obligation is substantive and its scope will likely be developed through subsequent decisions. Pending further clarification, practitioners should include an explicit AI-use statement at the front of any submission prepared with AI assistance and should attach a verification log for each cited authority.
Our team advises law firms, legal technology companies, and regulated entities on AI governance, litigation risk arising from AI tool deployment, and compliance with emerging judicial disclosure requirements. We work with a dedicated network of partners in AI law, legal tech, and regulatory affairs. Contact us to discuss how these guidelines affect your practice or your AI product offering. Types of work we handle or can assign to a partner include: AI governance policy drafting, litigation support on AI-related disclosure disputes, legal technology vendor due diligence, AI tool terms-of-service review, and training on judicial AI guidelines.
Source: Guerin v O'Doherty (Approved) [2026] IECA 48, Court of Appeal of Ireland, judgment of Ms Justice Costello delivered 26 March 2026, BAILII: https://www.bailii.org/ie/cases/IECA/2026/2026IECA48.html, confirmed 29 April 2026.
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