Anthropic’s Claude Opus 5 has reportedly outperformed human accountants on a set of accounting tasks in a new Mercor study, completing every test with perfect accuracy in less than 10 minutes. The results highlight the rapid progress of AI in structured professional work, although the researchers say the findings do not mean accountants can be fully replaced.
The study, titled “Human Baselines for Benchmarks: AI Now Outperforms Junior Accountants,” compared several AI models with 12 licensed CPAs who had an average of about 5.5 years of accounting experience.
Claude Opus 5 achieves 100% accuracy
The researchers asked the accountants to complete four month-end accounting scenarios using realistic company files. Participants had to search documents, identify relevant figures, perform calculations and present their answers in tables.
Human participants achieved an average accuracy of 37%, with individual results ranging from 0% to around 90%. Most accountants took between 30 and 180 minutes to complete the tasks.
Claude Opus 5 achieved 100% accuracy across all 20 reported attempts, with every task completed in under 10 minutes.
The study also highlighted a major cost difference. Using the US median accountant wage, Mercor estimated that human accountants cost $10.35 per rubric criterion completed, compared with $0.21 for Claude Opus 5.
Elon Musk reacts to Claude Opus 5 results
The findings attracted attention from Elon Musk, who shared a post about the study on X.
“Super Intelligence (fka AI) is now acing accounting tests,” Musk wrote.
The results also show how quickly AI performance has improved. Mercor said leading AI models were scoring below the average human accountant around 18 months earlier. OpenAI’s o3 later passed the 37% human average, while GPT-5 reached about 69%.
Does this mean AI will replace accountants?
Mercor cautions against interpreting the results as evidence that AI can perform an accountant’s entire job.
The researchers said the benchmark focused on tasks that AI systems are particularly suited to, including following detailed instructions, searching through large amounts of information and processing complex requirements.
Accounting jobs also involve client communication, teamwork, asking questions and applying knowledge from previous experience, areas that were not tested.
The study nevertheless suggests that AI could increasingly handle structured accounting work and potentially improve productivity across the profession.
