AI Is Already Inside Word. Pick Which One on Purpose.
Copilot, ChatGPT and Claude can all sit inside Word now, and there are two admin screens that decide which one your people use and whose account it runs on.
By John Martines · September 27, 2026 · 7 min
OpenAI's ChatGPT add-in reached Word on September 17 on every plan, Free included, and turns on by default October 1, 2026. Claude has its own Word add-in, and Copilot is already there. Here's the simple decision for a small business, and the two places to set it before October 1.
This isn't a question of whether your people will use AI in Word. They already can. The question is which one, and whose account it's signed into.
On September 17, OpenAI brought its ChatGPT add-in to Word. It already worked in Excel and PowerPoint. It's available on every ChatGPT plan, including Free, and OpenAI set it to be enabled by default starting October 1, 2026. Claude has its own Word add-in. Copilot is built into Word for anyone with a Microsoft 365 Copilot license.
Three assistants. One ribbon. Somebody should decide.
ChatGPT for Word. OpenAI says the add-in can draft from notes, summarize, revise selected text and clean up headings. People install it from Microsoft Marketplace and sign in with a ChatGPT account — any ChatGPT account. Free users get it, subject to usage limits. The October 1 default applies to eligible ChatGPT workspaces that haven't set it themselves, and OpenAI says workspace admins can turn it off in the ChatGPT admin console before or after that date. Microsoft 365 admins separately control whether the add-in can be installed.
Claude for Word. Anthropic's documentation lists it as generally available on the Pro, Max, Team and Enterprise plans. It isn't on the free plan. It can answer questions about a document with clickable citations, edit a selected passage without wrecking the formatting, work through comment threads, and put its edits in as tracked changes you accept or reject. Team and Enterprise owners control whether Claude can work across Word, Excel, PowerPoint and Outlook in one conversation, and that setting is off by default on those plans.
Copilot in Word. Microsoft said on September 25 that the per-user Copilot license covers Copilot inside Word, Excel, PowerPoint, Outlook and Teams. The metered agent features are a separate conversation — see "Your AI Bill Is About to Look Like a Phone Bill" on this site.
It's not the cost. The ChatGPT add-in costs nothing on a Free account.
It's the account. OpenAI says data from Business and Enterprise workspaces isn't used for training by default. On Free and Plus, conversations may be used to improve its models unless the person turns that off in their own settings. More to the point, a personal account isn't under your admin console at all. No company retention settings. No way to see what was pasted in. And when that employee leaves, the account leaves with them — along with whatever they drafted in it.
The cost is zero. So is the control.
There's a second, quieter wrinkle. Even the managed version isn't identical to the web app. Anthropic's documentation says Claude for Word doesn't inherit custom data-retention settings an organization has set, and its activity isn't included in Enterprise audit logs (Enterprise customers using Anthropic's Compliance API get add-in sessions there, in public beta). If your business has retention rules for a reason, check how each add-in actually handles them before you approve it.
And one warning Anthropic prints in plain language: only use the Word add-in with trusted documents. A downloaded template or a file from the other side of a deal can carry hidden instructions meant to steer the AI. That applies to any assistant reading a document, not just Claude.
You need both. Either one alone leaves a door open.
1. The AI vendor's admin console. This decides what your paid workspace allows. In the ChatGPT admin console, a workspace admin can turn ChatGPT for Word on or off. In Claude, Team and Enterprise owners control the cross-app setting under Organization settings, then Office agents, and Anthropic points admins to the Microsoft 365 admin center to manage who gets the add-ins. If you pay for one of these, go look at the setting before October 1 instead of inheriting the default.
The vendor console only governs your company workspace. It does nothing about an employee signing into Word with a personal Free account.
2. The Microsoft 365 admin center. This decides what can show up in Word for your people at all.
- Settings → Org settings → User owned apps and services → "Let users access the Office Store." Microsoft's documentation says this is on by default, which means users can download add-ins from Microsoft Marketplace themselves. Clear it, and they can't; only add-ins you deploy centrally appear. Microsoft notes this setting doesn't cover Outlook add-ins, which are managed separately in Exchange Online.
- Settings → Integrated apps. This is where you deploy the add-in you've approved, and assign it to the whole company, specific people, or a security group. You can change who has access later, or remove it.
Close the store, deploy the one you picked, and the ribbon shows what the company decided — not what somebody found on a Tuesday.
For a 20–50 person business, this is a one-meeting decision. Here's the order.
1. Start with what you already pay for. If you have Microsoft 365 Copilot licenses, Copilot is already in Word. If you run ChatGPT Business, use the ChatGPT add-in signed into that workspace. If you run Claude Team, use Claude for Word. The right assistant in Word is usually the one your company already manages, because that's where your admin controls, retention and offboarding already live.
2. Pick one for Word. Not three. Maybe a second for a named group with a real reason — the person who lives in contracts and wants tracked-changes redlining, say. Write down who and why.
3. Set both screens. In the vendor console, set the Word add-in to match your decision. In the Microsoft 365 admin center, turn off "Let users access the Office Store" if you want only approved add-ins, and deploy the approved one through Integrated apps.
4. Tell people in one paragraph. Which assistant. Signed in with which account — the company one, never a personal login on company files. What stays out: client contracts on anything unmanaged, anything regulated your business already protects. Where to ask.
5. Look again on October 2. Open Word on a staff machine. See what's in the ribbon. That's your real policy.
Here's how that plays out at Comfort Zone Heating & Cooling, the fictional HVAC company from the Playbook. Tony, the owner, already pays for ChatGPT Business for the office. Maya, the office manager, writes the service agreements and SOPs in Word. So Tony picks ChatGPT for Word, signed into the company workspace. Maya closes the Office Store in the admin center, deploys the ChatGPT add-in to the office group, and sends a four-line note: use the company login, not your personal one; nothing from a customer's contract goes into anything else. Carlos, the dispatcher, doesn't need it in Word at all. He doesn't get it.
One meeting. Done before the default flips.
Thinking the vendor switch is the whole job. Turning off ChatGPT for Word in your company's ChatGPT workspace doesn't stop an employee from installing the add-in from Marketplace and signing in with a free personal account — unless the Microsoft 365 side is set too. And closing the store stops new downloads; it's still worth asking who added an assistant on their own before you closed it. Two switches. Both on purpose.
The Applied AI Playbook covers this in Chapter 5 (the approved-tools table now has a row for Office add-ins) and Chapter 6 (Copilot, and the add-ins next to it).
Open Word tomorrow morning and look at the ribbon.
Whatever is sitting there, somebody decided it — you, a vendor, or an employee in a hurry.