OpenAI and Thrive have developed an advanced AI tax agent that achieves up to 97% accuracy when processing tax returns. This new technology, which has handled 7,000 returns across more than 30 accounting firms, significantly reduces preparation time by about one-third and enhances output by approximately 50%. While the AI easily deals with standard documents like W-2s and 1099s, its real innovation lies in addressing complex scenarios involving K-1s and rental schedules by tracing corrections and mapping data accurately, enabling effective error handling. This initiative is part of OpenAI’s broader focus on creating proactive, agent-driven systems to enhance professional tasks with minimal oversight, reflecting their commitment to integrating AI into critical operational areas like accounting.

Codex: Codex is OpenAI’s specialized AI model for coding and structured task automation. In the tax agent project, it converts repeated practitioner corrections into bounded engineering tasks with evidence, tests, and pass conditions to enable autonomous improvements.
OpenAI: OpenAI develops advanced AI models and tools focused on agentic systems and enterprise applications. In this news, it partnered with Thrive to co-develop a self-improving tax agent by integrating its Codex model into a practitioner-driven improvement loop for handling complex tax documents.
Tax AI: Tax AI is the self-improving agent developed by OpenAI and Thrive for tax return preparation. It processes complex forms by tracing sources, mappings, and corrections, turning human feedback into iterative model enhancements within a controlled environment.
Thrive: Thrive Holdings acquires and operates service businesses in accounting and IT, embedding AI technologies to transform operations. It collaborated closely with OpenAI on Tax AI, applying the system across its network of accounting firms to address real-world tax preparation challenges.

Agentic AI Focus: OpenAI is advancing models toward proactive, agent-driven systems that execute complex, multi-step professional tasks with minimal supervision.
AI Enterprise Integration: OpenAI has been embedding researchers and engineers directly into partner service firms to accelerate AI adoption in core operations like accounting and tax workflows.