// The guide

Claude for Excel: the complete guide.

2026-07-15 · 4 min read · by Nabil BA-MOH

You inherited the workbook. Forty tabs, formulas referencing formulas referencing a sheet someone deleted in 2023, and a #REF! error blinking where a number used to be. You know the rule: touch one cell wrong and the whole model quietly lies to you for the next six months.

That fear — change something without breaking everything — is exactly what Claude for Excel was built against. It's Anthropic's official add-in, a sidebar that reads and edits the workbook you have open. Announced as a research preview in October 2025, it's been generally available since May 7, 2026 as part of "Claude for Microsoft 365."

The two features that actually matter

Feature lists lie about what's important. In this add-in, two things carry everything else:

1. Cell-level citations. When Claude tells you something about your workbook — "revenue growth is driven by the assumption in B14" — the claim comes with clickable citations to the exact cells. You don't trust the AI; you click and verify. For anything audit-adjacent, this is the difference between a toy and a tool.

2. Dependency-preserving edits. Ask it to change an assumption and it updates the model preserving the formula dependency chain — not pasting values over your formulas, which is how a well-meaning intern (or a lesser AI) turns a living model into a dead one.

Everything else is built on that trust floor.

Debugging #REF! and #VALUE! to the root cause

The classic misery: a #REF! error five formulas downstream of the actual problem. Claude traces the chain back to the root cause instead of patching the symptom cell — and explains what broke, so the fix is a repair, not a cover-up.

Same muscle for archaeology: point it at the inherited workbook and ask "how does this model actually work?" — it navigates multiple tabs and reads the structure so you don't spend a day reverse-engineering someone else's logic.

What else it does

• Builds financial models and fills your existing templates.
• Sort, filter, pivot tables, charts, conditional formatting, data validation — the mechanical Excel work, on instruction.
• Multi-tab navigation of large workbooks.

And since it's part of Claude for Microsoft 365, the conversation can cross apps: the numbers it reads here can feed a PowerPoint deck or a Word document without copy-paste.

Install: two minutes

1. Open Excel → Insert → Get Add-ins → search "Claude by Anthropic" (AppSource listing WA200009404).
2. Add it, sign in with your Claude account. The sidebar appears.
3. On Team/Enterprise, an admin may need to deploy it via the Microsoft 365 Admin Center first (there's also a manifest-XML route for locked environments).

You need a paid Claude plan — Pro, Max, Team or Enterprise. No Free access, no surcharge on top of your plan.

Platforms and requirements

• Works: Excel on the web; Windows (Microsoft 365 build 16.0.13127.20296+); Mac (16.46+); iPad (2.51+).
• Doesn't: Excel 2016/2019 perpetual licenses, Android.
• Formats: .xlsx and .xlsm.

The limits, stated plainly

• No macros, no VBA, no data tables. If your model's logic lives in VBA, Claude works around it, not in it.
• Open workbooks only. It reads what you have open — it can't go fishing in your drive.
• Untrusted files are a prompt-injection risk — a hostile spreadsheet can carry hidden instructions. Be deliberate about what you open with the sidebar active.
• Human review stays mandatory for client deliverables and audit-critical calculations. The citations make that review fast; they don't make it optional.

FAQ