Thomson Reuters CoCounsel
Thomson Reuters · EFROS US AI Vendor Governance Index entry
Composite governance score
B = strong posture. Deployable in regulated workloads with documented compensating controls.
About this vendor
Legal AI assistant from Thomson Reuters (the parent of Westlaw and Practical Law). Acquired Casetext in 2023. Tightly integrated with Westlaw and Practical Law content.
- Enterprise tier
- CoCounsel Core, CoCounsel for Tax, CoCounsel for Legal (firm/individual licensing)
Twelve-axis governance scoring
Each axis is scored Yes / Partial / No / N/A against public evidence — vendor trust portals, BAAs/DPAs, SOC 2 report cover pages, published methodology documents. N/A applies when the axis is structurally inapplicable (foundation models, for example, defer Section 1557 to the downstream healthcare deployer).
| Axis | Status | EFROS note | Source |
|---|---|---|---|
| BAA / DPA available | Yes | CoCounsel is covered under Thomson Reuters' enterprise data-handling agreements. BAA scope addressed for firms with PHI in matter content. | Thomson Reuters Trust Center |
| Training-data opt-out | Yes | CoCounsel does not train models on customer data. Tenant isolation enforced. | Thomson Reuters CoCounsel Privacy |
| US data residency option | Yes | US data residency available for enterprise customers. | Thomson Reuters Trust Center |
| SOC 2 Type II report | Yes | Thomson Reuters Cloud Platform (which hosts CoCounsel) holds SOC 2 Type II and ISO 27001. | Thomson Reuters Trust Center |
| ISO/IEC 42001 attestation | No | No ISO/IEC 42001 attestation as of May 2026. | Public posture review |
| NIST AI RMF self-attestation | Partial | Thomson Reuters publishes AI Principles and governance documentation; no formal NIST AI RMF self-attestation. | Thomson Reuters AI Principles |
| Colorado AI Act readiness | Partial | Thomson Reuters documents the deployer responsibility model under Colorado AI Act. | Thomson Reuters customer documentation |
| HHS-OCR Section 1557 readiness | N/A | Legal-vertical positioning. | Thomson Reuters CoCounsel positioning |
| FRB SR 11-7 readiness | N/A | Legal-vertical positioning. | Thomson Reuters CoCounsel positioning |
| ABA Formal Op 512 readiness | Yes | Thomson Reuters publishes ABA Op 512 alignment documentation specific to CoCounsel deployment. | Thomson Reuters CoCounsel ABA Op 512 documentation |
| Subprocessor list public | Yes | Subprocessor list published as part of Thomson Reuters Cloud Platform terms. | Thomson Reuters Subprocessors |
Trust-center maturity
Thomson Reuters Trust Center is mature for cloud-platform compliance; AI-specific governance for CoCounsel is documented but less granular than the platform compliance.
Source: Thomson Reuters Trust Center
Deep dive
Overview
CoCounsel benefits from the parent Thomson Reuters compliance stack — well above what most legal-vertical AI vendors offer on their own. Tight integration with Westlaw and Practical Law content reduces hallucination risk on legal research workflows. The governance posture is more mature than Harvey on platform fundamentals; the workflow differentiation depends on firm preference.
Strengths
- Inherits Thomson Reuters Cloud Platform compliance stack
- ABA Op 512 alignment documented
- Tight integration with Westlaw / Practical Law — citation grounding
- Mature subprocessor transparency
Weaknesses
- No ISO/IEC 42001
- No formal NIST AI RMF self-attestation
- Pricing structure is more complex than per-seat alternatives
Best-fit use case
Firms already standardized on Westlaw and Practical Law, where CoCounsel's content integration delivers operational value beyond raw generative drafting.
Avoid when
Firms standardized on Lexis content — CoCounsel's research integration value depends on Westlaw/Practical Law alignment.
Operator's take
Deploy Thomson Reuters CoCounsel when firms already standardized on Westlaw and Practical Law, where CoCounsel's content integration delivers operational value beyond raw generative drafting. The composite score of 80 (grade B) reflects a defensible posture for regulated US workloads. Skip the vendor when firms standardized on Lexis content — CoCounsel's research integration value depends on Westlaw/Practical Law alignment. In every deployment, treat the cells above as a snapshot — the acquisition that gets to production safely is the one that re-verifies the trust-center posture before contract signature and rebuilds the matrix at renewal.
How this scoring is computed
The composite score blends eleven scoreable axes (BAA, training opt-out, US data residency, SOC 2, ISO/IEC 42001, NIST AI RMF, Colorado AI Act, Section 1557, SR 11-7, ABA Op 512, subprocessor transparency) with the trust-center maturity score. Axes marked N/A are excluded from the denominator so vendors are not penalized for sector-inapplicable axes. The vendor's primary sector amplifies the most relevant axes — healthcare vendors weight Section 1557 ×2, legal vendors weight ABA Op 512 ×2, banking vendors weight SR 11-7 ×2 — so the composite reflects what matters in the actual buying context.
Read the full methodology →Disagree with this scoring?
EFROS publishes scoring rationale per cell with a public source. If you have evidence that a specific axis should score differently — a new BAA, a new certification, a documented policy change — submit a formal challenge below. We re-score and publish the result with the next quarterly edition (or as a mid-quarter changelog entry if the change is material).
Disagree with a score?
Every cell in the EFROS Index is source-cited. If you have a public source that contradicts a score for Thomson Reuters CoCounsel, submit a formal challenge — we re-verify against the source and respond within 14 days.
Other vendors in Legal AI
Same category, scored on the same twelve axes. Useful for head-to-head shortlisting.
Take the scoring into production
The Index tells you the posture. These engagements turn the posture into a deployable program — vendor selection, governance policy, sector overlay, audit-ready evidence.