CoCounsel Tax and Audit Platform Gets Agentic Upgrade

Thomson Reuters launched a rebuilt CoCounsel tax and audit platform on Oct. 22, an agentic AI system built to carry out tax and audit work from source documents to finished, review-ready results. The new CoCounsel tax and audit release moves beyond answering questions: it plans assignments, runs calculations and produces documents for professional review. It is available now to all customers in the United States.

The CoCounsel tax and audit launch targets a hard problem in professional services. A mathematically correct answer can still be wrong if the system applies the wrong tax rule, misses client circumstances or fails to explain its reasoning. "They expect close to perfection with any tool that they use," David Wong, the company's chief product officer, said of tax accountants during a briefing.

Unlike its predecessor, which was organized around individual tasks, the rebuilt system breaks complex requests into steps and picks the tools and information needed to carry them out. Professionals still must review and verify the results. Every output draws on Checkpoint research, the company said, and the platform provides citations, assumptions and calculations so reviewers can assess its conclusions before approving the work.

What the CoCounsel tax and audit platform can do

CoCounsel tax and audit functions now include code execution and verified calculations for depreciation, amortization, required minimum distributions, qualified business income, threshold checks and multi-scenario comparisons. The features are aimed at tax professionals who need calculations, analysis and draft deliverables tied to relevant authority. The platform brings client information, engagement activity and workflow context together in one place.

It can produce multi-tab Excel workbooks with live formulas and a documented assumptions tab, and draft memos and other documents in Word and PDF formats. It can also update spreadsheets and documents that professionals upload, following the firm's own workpaper templates. The platform has native Model Context Protocol connectivity, so it can operate inside other applications, and it integrates with UltraTax, Engagement Manager, Guided Assurance, Ready to Review and Ready to Advise.

CoCounsel tax and audit: built for judgment calls

The company says the new CoCounsel tax and audit system is built to get judgment calls right. Tax and audit work is full of them: which rule applies, how a client's specific facts should be interpreted, what authority governs a given period. The platform grounds every calculation in the cited authority and carries that reasoning through to a finished result, with enough visibility into the process that a professional can validate the work.

In a demonstration, David Ragones, head of product for direct tax and audit, showed the CoCounsel tax and audit platform using a commercial loan agreement and a firm's spreadsheet template to produce an amortization schedule for a $5 million loan. The example included changing interest rates, a lump-sum payment and a balloon payment at maturity. The research database behind it is Checkpoint, Thomson Reuters' collection of more than 12 million primary-source and analytical documents, maintained by hundreds of specialists. The platform's Checkpoint research grounding means every answer is cited and every output is defensible, the company said. The platform supports multiple AI models.

Availability and the bigger AI push

The company launched the first CoCounsel Tax & Audit in March 2025, and says thousands of firms have since built it into daily workflows, with average time savings of 32% per task. The rebuilt release is the first of a new wave of agentic AI systems the company is embedding across its legal, tax, risk and compliance products, developed over more than a year and accelerated by its acquisition of Materia, an AI startup focused on agentic systems for tax and accounting.

Wong framed the launch as a step past rebranded assistants. "Building AI for professions is much harder than trying to build for general purpose productivity or helping you to summarize emails or helping you book concert tickets," he said. "AI for tax and audit and accounting is hard." For tax professionals, the question is whether the CoCounsel tax and audit upgrade can turn that difficulty into reliable, defensible work product.