In September 2025, OpenAI published a landmark paper titled “Why Language Models Hallucinate,” and the findings should concern anyone considering an AI-generated prenuptial agreement. The research proves that AI hallucination is not a temporary bug that will be fixed with better technology — it is a mathematical certainty that can never be eliminated.
What Does This Mean?
AI language models work by predicting the most statistically probable next word. They do not “know” facts or “understand” law. When the information they need is rare in their training data — like Illinois and Missouri prenup enforceability rules, local judicial interpretations, or complex financial structures — they fabricate answers with the same confidence as accurate ones.
OpenAI’s own data shows that newer, more advanced models actually hallucinate more, not less:
- o1 model: 16% hallucination rate on factual queries
- o3 model: 33% hallucination rate
- o4-mini: 48% hallucination rate
Why This Matters for Prenuptial Agreements
Prenuptial agreements must comply with state-specific rules about financial disclosure, voluntariness, fairness, and execution formalities. These rules vary significantly between states, and courts interpret them differently at the county level. This is exactly the kind of rare, nuanced legal knowledge where AI performs worst.
An AI tool will never tell you “I don’t know.” Instead, it will guess — and sound so confident that it persuades you the answer is correct. For something as important as the legal document protecting your financial future, that level of risk is unacceptable.
What You Can Do
If you are engaged and considering a prenuptial agreement, we encourage you to learn more about why working with an experienced attorney matters:
- Register for our FREE workshop: “Why AI and Online Forms Fall Short on Prenups” — Wednesday, April 8, 2026 at 7:00 PM Central, hosted by Attorney Zach Hunsinger.
- Read our full presentation: “Why Choose Hunsinger Law Group Over AI or Online Prenup Services” — a detailed breakdown of the research and what it means for your prenup.
- Schedule a consultation: Talk with us about your specific situation. No pressure, no templates — just honest guidance.
An attorney doesn’t guess. An attorney knows your state’s law, advises you on what works, and is professionally accountable if something goes wrong. An algorithm has no license to lose and no duty to you.
Source: “Why Language Models Hallucinate,” Adam Tauman Kalai, Edwin Zhang, Ofir Nachum, Santosh S. Vempala. OpenAI, September 2025.