OpenAI and Thrive Holdings have built a tax preparation AI that essentially teaches itself to get better. The system, deployed across Crete’s network of more than 30 accounting firms, started with a 25% accuracy rate at launch and climbed to 97% through autonomous feedback loops. The Tax AI uses OpenAI’s Codex models to transform real-world usage data into improvement signals, letting the system refine itself continuously without a team of engineers scrambling to patch every identified error.

From rough draft to near-perfect in six weeks

At launch, only 25% of returns hit a 75% accuracy threshold. Six weeks later, that figure jumped to 86%. The system kept climbing from there, eventually reaching up to 97% accuracy on drafted tax returns.

Preparation time dropped by roughly one-third, and overall throughput increased by approximately 50%. The AI produces tax engine submissions that are ready for human review, allowing tax professionals to focus on direct client interaction and complex judgment calls.

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