Claude in Excel is the spreadsheet version of Claude, Anthropic’s AI model that normally works in a chat window or via the API.
The add-in places Claude in a sidebar next to your worksheet: you ask questions about an open workbook and get answers with references to specific cells, and you can change assumptions without breaking formulas.
The add-in does more than answer questions. Claude explains formulas, changes values while keeping the underlying calculations intact, tracks down errors and builds new models or fills in existing templates.
You install it via Microsoft AppSource, and it requires a paid Claude plan, with some restrictions on supported Excel versions.
What the add-in can’t do matters at least as much as what it can, especially for work where a mistake has financial consequences.
What is Claude in Excel?
Claude in Excel is an official Anthropic add-in that places Claude as a sidebar in Microsoft Excel, so you can work with the model without switching applications. The add-in reads the open workbook, including multiple sheets, cell values and formulas.
Answers come with cell references that take you straight to the cell in question, so an explanation stays verifiable instead of being a claim you have to chase up yourself. The add-in is generally available, no longer in beta, for users with a Pro, Max, Team or Enterprise plan.
What can you do with Claude in Excel?
With Claude in Excel, you can ask for an explanation of a formula and change an assumption without breaking the rest of the model. You can also trace the source of an error, build a new model or fill in a template.
With a question such as “how is the revenue in cell C42 calculated?”, Claude traces the formula back to the underlying assumptions and shows which cells feed into it.
If you ask it to change the discount rate from 5 to 8 per cent, Claude updates the dependent calculations as well, so you don’t have to check every cell yourself.
Debugging works the same way: asking about the cause of a #REF or #DIV/0 error gets you an explanation down to cell level.
For new work, Claude populates an existing template with your own figures, or builds a complete model from a description, for example a three-statement model from a trial balance. The add-in also carries out ordinary Excel actions: sorting, filtering, adjusting pivot tables and applying conditional formatting, all on request.
For users who work a lot with financial data, there are separate connectors to sources such as S&P Global, LSEG and Daloopa, which bring external market data straight into the worksheet.
How do you install Claude in Excel?
You install Claude in Excel via Microsoft AppSource, where Anthropic’s official add-in is listed as Claude for Microsoft 365, a single add-in for Excel, PowerPoint, Word and Outlook. Choose “Get it now” there. After installation, open the add-in from the Add-ins menu in Excel and sign in with your existing Claude account.
The add-in works in Excel on the web and in the desktop versions from a certain build onwards: Excel for Windows with a Microsoft 365 subscription from build 16.0.13127.20296 and Excel for Mac from version 16.46. Excel on iPad and Excel on Android are not supported, and neither are Excel 2016 and 2019 with a perpetual licence.
For teams, an administrator can deploy the add-in centrally via the Microsoft 365 Admin Center, so employees don’t have to install it individually.
What are the limitations of Claude in Excel?
Claude in Excel doesn’t support macros, VBA code or Excel data tables. Work that relies on any of those three falls outside what the add-in can take over.
Anthropic itself advises against using the add-in for final client deliverables without human review, for audit-critical calculations without verification, and for models with highly sensitive or regulated data without appropriate safeguards. That standard of review applies to any AI application; here, Anthropic states it explicitly. In LearnLLM’s Claude Course, you learn how to make that review a fixed part of your work with Claude, including Claude in Excel.
How much does Claude in Excel cost?
Claude in Excel is included in an existing paid plan and has no separate price. You need Pro, Max, Team or Enterprise; with a free account, you won’t see the add-in.
Is Claude in Excel safe for sensitive data?
Claude in Excel is safe enough for most business data, provided you know two things. Anthropic deletes input and output within 30 days of processing, and the chat history is stored locally in your browser instead of being synced to a server.
The bigger concern is prompt injection. External files, such as downloaded templates or files supplied by clients, may contain hidden instructions. Anthropic itself warns that those instructions can trick the add-in into extracting data or changing cells without you intending it.
So only use the add-in on worksheets whose origin you trust, and check every proposed change before you confirm it.
Can an accountancy firm use Claude in Excel?
Yes, Claude in Excel is useful for an accountancy firm, particularly for getting to grips with complex worksheets and tracking down errors in existing models.
The cell references with each explanation make it easier to trace an outcome back to the source data.
Anthropic itself explicitly excludes audit-critical calculations, so the add-in doesn’t replace checking work; it speeds up the preparatory work around it.
Does Claude in Excel replace an accountant or controller?
No, Claude in Excel doesn’t replace an accountant or controller, because the add-in produces a proposal that a person assesses, not a verified outcome. Anthropic itself names audit-critical calculations and final client deliverables as situations where review without verification is not enough.
The difference between an AI tool that speeds up work and an organisation that knows when a second pair of eyes is mandatory is exactly what the AI Literacy Course focuses on: a fixed check for each type of task, instead of everyone deciding for themselves when to trust Claude in Excel.
Frequently asked questions about Claude in Excel
After installing Claude in Excel, questions often come up about limits and about use outside Excel.
Does Claude in Excel count towards your usage limit?
Yes, Claude in Excel counts towards your usage limit, because Anthropic links its use to your existing Claude account and applies the same limits. If you use Claude a lot in the chat, you’ll have less room left in Excel. Claude automatically condenses long conversations in the add-in into a new conversation, so you don’t hit the context window limit.
Does Claude also work in Google Sheets?
Claude also works in Google Sheets, but through a separate extension and not through the Excel add-in. You install that extension from the Google Workspace Marketplace, and it uses an API key from the Claude Console, which you enter again for each new spreadsheet. In a cell, you call Claude with the function =CLAUDE() or, for conversations with several turns, =CLAUDEMESSAGES(). Usage runs through the API and not through your Claude plan.
Can you set fixed instructions in Claude in Excel?
Yes, you can set fixed instructions in Claude in Excel via Settings in the sidebar, in the Instructions field. Whatever you enter there applies to every conversation in Excel, such as a number format with thousands separators or a fixed currency. The instructions in Excel are separate from those in Word or PowerPoint, so you set them up separately for each program.
Can Claude in Excel work together with Word and PowerPoint?
Yes, Claude in Excel shares context with the Claude add-in in Word and PowerPoint, and also with the one in Outlook. According to Anthropic, one conversation can therefore cover your open workbook and, for example, your presentation at the same time. That way you can put an analysis from Excel into a slide without retyping the figures; afterwards, do check that the numbers in the slide match the workbook.
