Model Release
OpenAI and Thrive Build Self-Improving Tax AI with Codex
Tax AI processed 7,000 returns for Crete's 30+ accounting firms, improving accuracy to 86% correct field completion within six weeks.
Image: OpenAI
OpenAI and Thrive Holdings co-developed Tax AI, a self-improving system for Crete’s network of 30+ accounting firms, using Codex to automate tax return preparation. The system helps practitioners save about a third of their time on tax preparation, drafts returns with up to 97% accuracy, and increases throughput by about 50%. Tax AI processes millions of underlying documents for medium- to large-complexity filings, which often involve messy data sources, prior-year documents, and manual extraction and calculation. The system automates much of the time-intensive process of preparing 1040 and 1041 tax returns. Even more compelling than the efficiency gains is that the system itself is measurably better than the version that was first deployed three months ago. OpenAI and Thrive collaborated over the past six months to build Tax AI alongside and for Crete’s accounting firms to help prepare increasingly complex tax returns. Instead of relying on engineers to find and fix each failure, Tax AI uses Codex to turn production use into structured signals that fuel autonomous improvement. *Source: [openai](https://openai.com/index/building-self-improving-tax-agents-with-codex/)*
Key points
- Tax AI processed 7,000 tax returns across the Crete firms that participated in the pilot this tax season.
- Tax AI saves practitioners about a third of their time on tax preparation.
- Tax AI drafts returns with up to 97% accuracy and increases throughput by about 50%.
- At launch, only a quarter of returns were at 75% correct field completion, but within six weeks, 86% hit that mark.
- Tax AI handled simpler work, like W-2s and 1099s, and moved into more complex returns with K-1s, schedules, and harder edge cases.
- As Tax AI expanded into more complex filings, the share of scored returns reaching 75%, 90%, and full completion continued to rise through tax season.