Claude For Excel

Claude for Excel is Anthropic's add-in that puts Claude in a sidebar inside Excel. It reads the open workbook, answers questions with cell-level citations you can click to jump to the referenced cell, changes assumptions while keeping formula relationships intact, traces errors to their root cause, and builds or populates models from a natural-language description. It installs as part of Claude for Microsoft 365, alongside the PowerPoint, Word, and Outlook add-ins.

It is aimed at finance and operations people who live in models, and at founders and analysts who inherit spreadsheets they did not build. Developers reach for it when the data already lives in a workbook and a script would be overkill.

Highlights

• Cell-level citations. Ask how a number in C42 is derived or which assumptions drive gross margin, and the answer cites specific cells you can navigate to.
• Safe value updates. "Change the discount rate to 8% and update dependent calculations" edits inputs and lets downstream cells recompute rather than overwriting formulas with values. Claude warns before overwriting existing data.
• Debugging. Find the source of a #REF! in the summary tab or trace why H15 returns #DIV/0, across multi-tab workbooks.
• Model building. Populate an existing template (an LBO with a given purchase price and leverage, for example) or generate a three-statement model from a trial balance.
• Native Excel operations. Sort, filter, edit pivot tables, apply conditional formatting, and create data-validation dropdowns by asking.
• Connectors, skills, and cross-app context. Pull external data through connectors such as S&P Global, LSEG, and Daloopa; skills enabled in your Claude settings apply automatically; and one conversation can span Excel, PowerPoint, Word, and Outlook.

In an AI-assisted workflow

The add-in is strongest as a reviewer and editor of a workbook you already have open, rather than a from-scratch generator. A typical loop: open a trusted copy, ask Claude to explain the model, then make targeted changes and verify each.

Walk me through how the terminal value on the DCF tab is calculated,
citing cells. Then flex the growth rate from 5% to 10% and show me the
impact on terminal value and equity value without changing any formulas.

Persistent instructions in the add-in's settings ("format numbers with thousand separators", "always bold column headers") apply to every Excel conversation and are separate from the instructions you set in PowerPoint or Word. Long sessions are auto-compacted into new conversations so you do not run out of context.

Good to know

Availability, per Anthropic's docs as of September 2026: generally available on Pro, Max, Team, and Enterprise; not on Free. Install it yourself from the Claude for Microsoft 365 listing on Microsoft AppSource, or have an admin deploy it through the Microsoft 365 Admin Center (a custom manifest XML is available for tenants that block the Office Store). Organizations on Amazon Bedrock, Google Cloud Vertex AI, Azure AI Foundry, or an LLM gateway can deploy it without individual Claude accounts, with models coming from that platform.

Supported builds: Excel on the web, Excel on Windows with a Microsoft 365 subscription (build 16.0.13127.20296 or later), and Excel on Mac (16.46 or later). Excel 2016 and 2019 perpetual licenses, Excel on iPad, and Excel on Android are unsupported because the add-in needs SharedRuntime.

Limits: data tables and macros/VBA are unsupported. The model list in the add-in is a curated subset of what claude.ai offers. Usage counts against your Claude account's normal limits. Chat history is stored locally in the browser via IndexedDB, not on Anthropic's servers, and does not sync across devices; inputs and outputs are deleted on the backend within 30 days. Activity is not included in Enterprise audit logs, and the add-in does not inherit custom retention settings.

If you want the same work done on files rather than inside the open workbook, Cowork can operate on a folder of spreadsheets; for web-based data sources, Claude for Chrome can fetch it. Compare against Microsoft Copilot if you are already paying for Copilot seats.