Claude in Google Sheets: build the monthly client report in place

Many small businesses run their numbers in a spreadsheet that one person understands. Once a month that person rebuilds the summary, fixes broken formulas and writes a note for the partners. On October 6, 2026, Anthropic released a Claude add-on that works inside Google Docs, Sheets and Slides, in the file you already have open. That makes the monthly report a good first job to hand over, with you still approving every change.

What changed

Until now, Claude meant uploading a copy to claude.ai and pasting the answer back. According to Anthropic's announcement, Claude now opens in a sidebar next to the file, reads it, sees your selection and edits it directly.

The details that matter, from the Claude help article:

• Sheets: Claude writes and fixes formulas, builds pivot tables and native charts, adds tabs, and can move a range into Python for cleanup and write the result back.
• Docs: small fixes happen in place; larger rewrites arrive as suggestion cards you apply or dismiss.
• Approval by default. The default mode is "Ask before edits": every change shows as a card and waits. "Accept all edits" lets Claude finish the task, but adding links, inserting web images and changing access still need your approval every time.
• Narrow permissions. The add-on asks Google for two permissions only: to show the sidebar, and to view and manage the files it runs in. It does not ask for Drive, Gmail, Calendar or contacts.
• Plans. Beta, on Pro, Max, Team and Enterprise. One install covers all three apps.

What it means for the monthly report

Picture an accounting office of 9 that bills clients by the hour. On the first working day of each month, the office manager pastes the time tracking export and the invoicing export into a Google Sheet, matches them by client, checks which retainers ran over, and writes a short summary for the two partners. It takes a morning, and only she knows the formulas.

With the add-on, she opens the same sheet and asks Claude to match hours to invoices by client, add a summary tab with hours, billed amount and effective hourly rate per client, flag every retainer more than 10% over its budget, and chart the top ten clients. Each step comes back as a card she reads before it lands. Then she asks for a five line summary in the partners' Google Doc.

Three things change. The knowledge moves from her head into a written request anyone can rerun. The work stays in the partners' file, with every edit in version history. And a formula quietly pointing at the wrong column is now something she checks on a card, not something she hunts for later.

What does not change: this is a session, not an automation. Claude cannot create triggers or scheduled refreshes, and it stops if the sidebar closes.

How to set it up

1. Check who installs it. In the Google Admin console, go to Apps, Google Workspace Marketplace apps, Apps list. Either allowlist Claude so people can install it, or admin install it for one group. Google's admin help has the exact screens; admin install works even when user installs are blocked.
2. Install and sign in. Open any Sheet, go to Extensions, Claude, Open Claude, approve the two permissions and sign in with the Claude account on your business plan.
3. Convert the files. Excel files do not work. Save the exports as native Google Sheets first.
4. Write the report request once. Spell out the columns, the matching rule, the 10% threshold and the tabs. Save it in the sheet's first tab for next month.
5. Run it on last month first. Keep "Ask before edits" on and compare every number with the report you already sent.
6. Add the summary in Docs. Ask for the short version in the partners' Doc and check each figure against the sheet.

Costs, limits and risks

On the pricing page, Team Standard costs $20 a seat a month billed annually or $25 monthly, for 2 to 150 seats. Pro is $17 a month billed annually or $20 monthly. Three people on Team Standard, billed annually, come to 3 × $20 = $60 a month. As an estimate, if the report drops from four hours to one and a half, that is about 30 hours a year back for one person; test it on your own file before you count on it.

The limits to know first:

• Beta. Reworked notes Anthropic's own warning that some features may be limited or unreliable.
• Six minutes per operation, the open file only, no Firefox, and no reading of comments in Docs.
• Terms. Team and Enterprise fall under commercial terms; Pro and Max under consumer terms. Anthropic says it does not train on this content and deletes inputs and outputs within 30 days. The extension does not follow your custom retention settings.
• Sensitive data. The help article says not to use it with protected health information. A clinic should keep patient sheets out of it.
• Files from outside. Claude treats file content as data, but review its proposed actions on any file a client sent you.
• Two Google accounts in one browser cause failed actions. Use a browser profile with one account.

9to5Google points out that Gemini, already built into Workspace, can do much of this. The add-on fits best where the team already pays for Claude.

Should you do it now

Do it now if one person rebuilds the same report every month, your files are native Google Sheets and the team already has Claude Team. Wait if your numbers live in Excel or your Workspace admin is not ready to allowlist a beta app. Skip it for anything with health or similar regulated data, and skip it if you need the report to run on a schedule without anyone opening the file.