Dayjob: Tax – evaluating AI agents on 50 professional tax assignments

Surge AI introduced DAYJOB: Tax, a benchmark of 50 environments across eight tax practice areas in which agents receive client requests and supporting records and must produce returns, workpapers, reviews, or advice. Claude Sonnet 5.5 leads the leaderboard with a 10.8% pass rate at a 95% rubric threshold, followed by Claude Fable 5.1 at 9.6% and Claude Opus 5.5 at 9.2%. The post illustrates the difficulty with examples in which agents missed a home-sale exclusion deadline and assumed a couple was unmarried without verifying their marital status.