Lesson 10
Estimated time: 5 minutes
Learning objectives
By the end of this lesson you'll be able to:
- Recognize what Claude does inside Word, Excel, PowerPoint, and Outlook
- Move work between the apps with one Claude conversation
- Decide when to do the work in Cowork versus inside the document
Collaborate with Claude across Microsoft 365 apps
Key takeaways
- Claude lives inside the document. Claude shows up as an add-in inside Word, Excel, PowerPoint, and Outlook, working on the files and spaces you have open.
- One conversation can carry context across the apps. Build the analysis in Excel and hand it to PowerPoint to make the slide. Use the Word memo as the source for the draft Outlook reply.
- Claude in Cowork and Claude in M365 are different tools for different moments. Claude inside Cowork builds finished deliverables across many sources. Claude inside M365 is for refining, debugging, and shaping a file you're already working on — and for carrying context from that file into other documents you're building.
What Claude does inside each app
Excel. Analyze data, write formulas, debug #REF! errors and circular references, run scenario tests without breaking the model, build a sheet from a template, cite back to specific cells. The strongest move: "Pull the actuals from the Q3 sheet, compare them to the Q3 plan in the same workbook, and write the variance commentary in column F next to each line item."
PowerPoint. Read your slide master, fonts, and color scheme, then build slides that match. Generate native, editable charts (not pasted images). Operate on whatever slide you have selected. The strongest move: "Take the analysis I just did in Excel and turn it into a three-slide deck for the QBR, using our deck template."
Word. Draft, revise, and reformat in place. Work with comments and tracked changes. Pull context from connected sources to ground the draft. The strongest move: "Draft the executive summary based on the body of this memo and the source data referenced in the appendix."
Outlook. Triage incoming mail with context from the rest of your work. Draft replies that reflect prior threads, calendar context, and recent decisions.
Move work across the apps in one conversation
The cross-app move is where M365 plus Claude starts to feel different from working in any single app. You're not just working on one document — you're carrying its context into the next one.
- Outlook → Word. A client brief lands in your inbox. "Open the brief in Word and start the memo from our firm template." Word launches with the attachment open and the email thread already loaded in the sidebar. Claude already knows what the sender asked for.
- Word → Excel. Partway through the memo you need the numbers behind it. "Build the market-sizing model behind option 2." Excel opens, pulls the assumptions from the brief Claude just read in Word, and builds a multi-tab model with formulas you can inspect.
- Excel → PowerPoint. "Turn this into the steering-committee deck in the client template." The deck builds in your slide master with native, editable charts with the updated numbers from Excel.
- Back to Outlook. "Find 30 minutes with the team before Thursday." The invite drafts with the attendees and waits for you to click Send.
When to use M365 versus Cowork
A useful rule:
- Reach for Cowork when the work pulls from many sources and ends in a deliverable. Building the brief from twenty source files, pulling a report together from Salesforce and three Slack channels, running a workflow on a schedule.
- Reach for Claude inside M365 when you're working in the Office files themselves — editing in place and carrying context from one app to the next.
Most real work uses both. Claude builds the first draft of the deck; you open it in PowerPoint and refine it with Claude in the slide. Claude pulls the data into the model; you open it in Excel and ask Claude to investigate the outlier you spotted. The two surfaces hand off cleanly — and the file is the file in both cases.
Try it now
First, install the Claude add-in for the Microsoft 365 app you use most — see Work across Excel, PowerPoint, and Word for setup and plan availability. Claude for Outlook is a separate beta with its own listing — see Claude for Outlook. If add-ins are managed by your IT team, check with them.
Open one of the M365 apps with a real document you're working on this week. Try one move with Claude inside the app — refine a paragraph, debug a formula, build a slide from a passage in a Word doc. The first time you see Claude operating on the document you're staring at, the difference from chat-then-paste lands.
What’s next
You've now seen Cowork everywhere it shows up — the desktop, the browser, and the documents themselves. Module 4 turns to the parts of using Cowork that matter once you're handing it real work: working safely, making sure the things you build behave, and sharing them with your team.