Thomson Reuters (TRI) CoCounsel Legal AI: 2.4x Usage in First Month

Thomson Reuters (TRI) said on its third-quarter 2026 earnings call on 2026-11-03 that in the first full month after the new CoCounsel Legal AI assistant went live, users completed 2.4 times the work of the prior version's peak [1]. That is a usage-intensity reading. The company has not disclosed revenue or profit contribution for this product on its own.

What CoCounsel Legal does

Thomson Reuters Corporation (TRI) sells information and software to professionals. Its segments include Legal, Corporate, Tax & Accounting and Reuters News. It mainly sells professional content and workflow software by subscription to law firms, corporate legal departments, accounting firms and government agencies. Westlaw, its case-law and statute research database, and Practical Law, its practice guidance, are the pillars of the legal business.

CoCounsel Legal is the legal AI assistant the company sells to law firms and corporate legal departments. Lawyers ask it questions or assign it tasks while doing legal research, reviewing documents and handling matters. It breaks a task into concrete steps, draws on Westlaw and Practical Law content, and produces research conclusions, document review results and tabular analysis. The new version (NextGen) is a product the company rebuilt in 2026. It can carry out multi-step tasks on its own and writes out the 10 to 30 steps it takes to answer a question [1]. The product is sold directly to legal customers and sits inside the company's core business.

From a time-savings estimate to product usage data

Public disclosure about this application started with an efficiency estimate and has now reached usage data from the product itself. On the 2024-08-01 second-quarter earnings call, management cited the company's own industry report and estimated that lawyers using the CoCounsel legal AI assistant saved 4 hours per week each, a figure it expected to grow to around 12 hours per week in a couple of years [2]. That was an impact estimate based on lawyer hours. The product was still in pilot rollout, and the company gave no usage figures for the product itself.

The company has since rebuilt CoCounsel Legal as the NextGen version. This is an upgrade of the same product; it was not renamed or folded into another product. By 2026-11-03, NextGen was generally available in the US, Canada and Australia, and most users of the CoCounsel Legal AI bundle had moved to the new version [1]. The company also gave usage readings specific to this product for the first time.

First-month usage readings and their limits

The NextGen usage readings cover the first full month after launch. In September, its active users grew more than 60% from August, users completed 2.4 times the work of the prior version's peak, and they were active 44% more days per month [1]. The company also said the product's net promoter score was more than double the prior version's best month, and that every usage and retention metric it tracks exceeded the prior version's best month [1].

These figures measure customer usage intensity, and every comparison is against the prior version. The 2.4 times figure refers to the volume of tasks users completed in the product. The company did not define how "work" is counted, so it should not be read as a 2.4 times gain in lawyer productivity or revenue. Part of the active-user growth comes from users migrating from the prior version, and the company did not split new users from upgrading users. The readings also cover only one month, and management itself said it is still early.

How usage could reach the financials

The financial effect of this usage has to be read through organic revenue growth in the Legal segment. Legal organic revenue grew 9% in the third quarter. Management named Westlaw and CoCounsel Legal together as the main drivers and did not split their individual contributions. The company's disclosed figure that generative AI products account for 34% of annualized contract value covers all product lines and cannot be attributed to CoCounsel alone.

One possible path: the more lawyers use the product, the more likely law firms and corporate legal departments are to renew and upgrade to premium bundles that include AI features, which would support the Legal segment's contract value and organic revenue.

On the cost side, the CFO said large language model costs are rising [1], and those costs are weighing on Legal segment margins. The company is offsetting this partly through premium bundle pricing. It is also moving compute-heavy tasks such as bulk document review and tabular analysis from external frontier models to its own Thomson models [1]. Management said speed and accuracy improved after the move and expects a cost advantage that would let CoCounsel Legal keep unlimited monthly pricing in many cases. It gave no cost or accuracy figures, and that advantage will only be realized as model capacity utilization approaches full load.

What to track next

The operating change that can be confirmed is that the rebuilt CoCounsel Legal was used more often and more deeply by lawyers in its first month, and customer reliance on the product is growing. That gives the Legal business a customer base for holding premium AI bundle pricing and unlimited monthly plans. The company has not separately quantified how much revenue the product brings in or whether it can protect margins while model costs rise. The next tests are whether the company discloses annualized contract value for CoCounsel Legal, paid seat counts, or the upgrade rate to premium AI bundles.

Application assessment

• CoCounsel Legal AI Assistant | Business position: core business | Stage: limited production | Scope: single business unit | Value type: revenue growth

Sources

[1] Drillr · Thomson Reuters Corporation (TRI) · 2026-11-03 · Earnings call

"Co-counsel legal NextGen users are completing 2.4 times the work versus the peak for the prior version and are active 44% more days per month."

[2] Drillr · Thomson Reuters Corporation (TRI) · 2024-08-01 · Earnings call

"But if you had a chance to read our future professionals report that we put out a few weeks ago, we quantified the impact this year from applying our CoCounsel legal AI assistant as 4 hours per week per lawyer, and we think that will grow to something like 12 hours per week in a couple of years’ time."