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AI & Automation

Microsoft Copilot for Legal: What UK Law Firms Should Consider Before Adopting It

James Moore7 min read

On 15 October 2026 Microsoft made Copilot for legal generally available: more than 20 legal-specific skills within Microsoft 365 Copilot, together with plugins from legal technology vendors. Where a firm already holds Copilot licences, some of these capabilities are likely to be available to its fee earners already.

This article sets out what it does, how it is licensed, where it falls short for a typical UK practice, and what should be in place before it is used on client matters.

What is Microsoft Copilot for legal?

It is the general release of the tool Microsoft previewed in April as Legal Agent for Word. It operates in two places:

  • In Word, on a single document: reviewing an agreement against your playbook (Microsoft's term; in practice, your firm's preferred positions on key clauses), proposing changes as proper tracked changes, and drafting from approved precedents held in SharePoint.
  • In Copilot Cowork, Microsoft's tool for multi-step work across files, emails and meetings: tracking obligations and deadlines across a set of contracts, comparing terms across agreements, building case chronologies, and turning meeting notes into minutes.

Microsoft states that it was developed with legal engineers, rather than being general-purpose prompts presented as legal tools. It also reports that around 1,800 users of the preview made close to 100,000 edits and retained roughly seven in ten of the suggestions. Those are Microsoft's own figures, drawn from its early-access users, and should be read as indicative rather than as independent evidence.

What licence do I need for Copilot for legal?

A paid Microsoft 365 Copilot licence is required. The free Copilot Chat included with Microsoft 365 does not provide these capabilities.

  • The Word plugin is included with the Copilot licence and is on by default for commercial Copilot users. Admins control it with a policy called “Legal Skills in M365 Copilot in Word” in the Microsoft 365 Apps admin centre.
  • The Cowork plugin, “Legal for Cowork”, has to be made available by an admin, and Cowork runs on usage-based billing with Copilot Credits on top of the licence.

The second point has budgetary consequences. Cowork usage is metered, so the cost is not fixed per user, and a spending limit should be set before it is enabled.

Firms wishing to evaluate it without committing to licences can use Microsoft's current offer of 25 free Copilot licences for 30 days, available until 31 December 2026. We have explained how that trial works and the auto-renewal condition to check.

How well does Copilot for legal suit a smaller UK firm?

For contract-heavy commercial work, the Word capabilities are of genuine practical value. Proposed amendments arrive as native tracked changes with formatting preserved, which addresses the principal shortcoming of general-purpose AI for document work.

The launch partners, however, indicate the intended market: Bloomberg Law, Trellis, iManage, NetDocuments, HighQ, Harvey and Relativity. That is predominantly US legal research and enterprise document management. The case and practice management systems most smaller UK firms use (LEAP, Clio, Actionstep, Smokeball) are not on the launch list, nor are the principal UK research services.

For conveyancing, family and private client practices, where matter work sits in a practice management system rather than in Word, the immediate benefit is therefore considerably narrower than the announcement implies. That may change as further plugins are released. At present, for most of the firms we support, it is principally a Word tool.

Does Copilot for legal protect client confidentiality?

Microsoft's position is that prompts and documents remain within the Microsoft 365 service boundary under enterprise data protection, that Copilot respects sensitivity labels, and that no content is used to train the underlying models. These are the same commitments that apply across Microsoft 365 Copilot, and they compare favourably with staff using consumer AI tools for client material.

The more significant risk lies elsewhere. Copilot works with whatever each user is already permitted to access. In many firms we review, SharePoint and file permissions have accumulated over years without audit. Copilot does not create that exposure, but it surfaces it readily: a query on one matter may draw on a document the fee earner was never intended to see, with obvious implications for confidentiality and information barriers.

There is also the regulatory position. The SRA's August 2026 warning notice on AI makes clear that responsibility for the work remains with the solicitor, whatever tool produced the first draft.

Microsoft itself states that the legal skills do not provide legal advice.

What should a firm put in place before adopting Copilot for legal?

  1. Establish whether it is already enabled. Where Copilot licences are in place, the Word plugin is likely to be live. Decide which users should have it and set the policy accordingly.

  2. Review permissions first. Audit access across SharePoint, OneDrive and Teams before widening Copilot use.

  3. Write down your preferred positions. The review is only as reliable as the positions supplied to it, and positions that exist only in a partner’s experience cannot be applied.

  4. Run a controlled pilot on live work before any wider rollout. The free trial offers a cost-free means of doing so before the end of the year.

  5. Set a Cowork spending limit before the plugin is made available.

  6. Update your AI policy to specify which work may and may not be processed through Copilot. Our template AI policy provides a starting point.

Sources

More on IT, cybersecurity and AI for solicitors on our law firms page.