Claude in Word is a Microsoft 365 add-in that puts Claude in a side pane next to your open document. It reads the file and answers questions with a click-through citation to the clause it used. It rewrites a selection without breaking formatting, and lands its edits as tracked changes. Anthropic opened the public beta in April 2026, then extended the add-in to every paid plan.
The difference with the chat window fits in one sentence. In a chat you copy the text out, paste it back and reformat it. In Word, Claude works inside your file, and every edit is still yours to accept or reject.
What exactly is Claude in Word?
Claude in Word is an Office add-in that sits in Word's ribbon and opens a conversation pane beside the document. Claude reads the text, comments, tracked changes, footnotes, tables and bookmarks of the single file you have open. It sees neither the other documents on your disk nor the rest of your workspace.
Six uses come up in Anthropic's documentation, and they are the ones teams actually reach for day to day.
Semantic navigation deserves a word of its own. Asking Claude to surface every provision touching data retention returns passages that may not contain those words at all. Anthropic's documentation lists the supported commands and the limits of each mode.
Installing the Claude for Word add-in
Installing it for yourself takes three minutes. Open the Claude for Microsoft 365 listing on the Microsoft AppSource marketplace, select the install button, then go back to Word. The add-in shows up under the Home tab on Windows and in the Tools menu on Mac. All that is left is signing in with your Claude account.
For a company-wide rollout, the Microsoft 365 administrator goes through the admin centre. They first allow Office Store access in the organisation settings. They then add the add-in from the integrated apps page, and assign it to the whole organisation or to specific groups. A full rollout can take up to twenty-four hours.
Which Claude plans and which versions of Word?
The add-in is available on the Pro, Max, Team and Enterprise plans, checked in November 2026. It does not exist on the free plan. Budget around 19 euros a month for Pro and around 23 euros per seat per month for Team on monthly billing, both detailed in our Claude plan breakdown. An organisation already routing its traffic through Amazon Bedrock, Google Cloud Vertex AI or Microsoft Foundry can deploy the add-in without individual Claude accounts.
| Version of Word | Add-in available |
|---|---|
| Word on the web | Yes |
| Word on Windows with a Microsoft 365 subscription, 2022 build or later | Yes |
| Word on Mac, 2022 build or later | Yes |
| Word 2016 and Word 2019 perpetual or volume licences | No |
| Word on iPad and Android | No |
| Files in the .doc format | No, save as .docx first |
Tracked changes, the feature that justifies the add-in
In tracked changes mode, Claude does not quietly rewrite your document. The original text stays visible as a deletion, the new text appears as an insertion, and everything is reviewable in Word's native review pane. You accept or reject line by line, and the usual undo shortcut still works.
That detail is what makes the add-in usable on documents that carry risk. An assistant that returns a rewritten paragraph in a chat window leaves you to compare by hand. A proposal sitting in the review pane is validated in three seconds.
Reviewing a contract without losing control
Contract review is the use case Anthropic puts forward, and it is also the one that pays off fastest. Claude summarises the commercial terms and flags provisions that drift from a standard position. It makes indemnification mutual on request, and works through reviewer comments one by one, replying in each thread.
Large firms have taken the subject seriously. Freshfields signed a multi-year agreement with Anthropic to deploy Claude across its thirty-three offices and co-build legal workflows, according to its April 2026 announcement. The areas named cover legal research, contract review, document drafting and due diligence.
Drafting inside the company template
The second use case is drafting inside an existing template. Claude picks up the document's heading and paragraph styles, populates tables in place without distorting the columns, and keeps numbering intact. You hand it a brief, a dataset or a thread, and it drafts the missing section in your template's shape.
At Tandem, proposals and master agreements live inside strict templates. The time sink was never writing the substance, it was reformatting after every paste. Drafting inside the file removes that step.
A persistent instructions field, in the pane's settings, sets the tone and conventions applied to every conversation in Word. Those instructions stay specific to Word and carry over to neither Excel nor PowerPoint.
Claude in Word or Copilot in Word?
Microsoft launched a legal agent for Word in April 2026, which compares a contract against an internal playbook and also produces tracked changes. It lives in the Copilot pane, needs no installation, and assumes a Microsoft 365 Copilot licence. We cover what the tool is really worth in our Copilot review.
The decision turns less on the feature than on the rest of your stack. A company already paying for Microsoft 365 Copilot would pay twice for a near-identical capability. A company whose teams already work in Claude gains continuity of context, since the Word add-in shares its conversation with the other Office applications.
The same logic applies to Claude in Excel, Claude in PowerPoint and Claude in Outlook. A brief that arrives by email becomes a Word document, then an Excel model, then a deck, without re-explaining the context at every step.
What the add-in cannot do
Anthropic explicitly advises against four uses, and the list is worth reading before rolling the add-in out to a team.
- Final deliverables sent to a client or a counterparty without human review.
- Litigation filings and audit-critical documents without verification.
- Replacing legal or financial judgement, which stays with the person who signs.
- Highly sensitive or privileged documents without proper access controls.
On top of that come the technical limits in the table above, plus a compatibility incident Anthropic has flagged. After the September and October 2026 Microsoft 365 updates on Windows, some users lost their chat history. Skills uploaded to the pane went missing too. The issue was still open in November 2026.
What Claude reads and what Anthropic keeps
Inputs and outputs are deleted on the backend within thirty days of receipt. A few hours of caching follow the deletion, so you can retrieve context from a recently closed document. Chat history is stored locally in the browser or app, with no sync across devices.
Two points deserve an IT department's attention. The add-in does not inherit an organisation's custom retention settings, and its activity does not appear in Enterprise audit logs. Enterprise organisations that have enabled the Compliance API do find Word sessions there, with no extra setup.
Clearing local history does not delete the messages and files Anthropic keeps. That nuance is worth writing into an acceptable-use policy before a rollout.
Stay in the chat, or install Claude in Word?
In June 2026 I described four levels of Claude usage inside a company. The entry level is the chat window, and most teams never leave it. It is also the level where the model does the least work for you, because you stay the middleman between the answer and the file.
Do not confuse the two routes to a document. Cowork produces a complete Word file from your context folder, as I set out in my edition on Cowork. The add-in works inside a document that already exists and that you very much do not want rewritten from scratch.
Our recommendation is straightforward. If your teams spend more than an hour a day in Word on contracts, memos or reports, install the add-in. Write a one-page positions memo, and make tracked changes mode the default. If Word is only an export format at the end of the chain, stay on Cowork and keep your budget.
Tandem supports more than 50 companies on these rollouts, and the tipping point is never the licence. It is the moment a team finally writes its review rules down. That is also what our Claude training covers.
