Copilot 365 Not Writing into Excel

Question

I have M365 Copilot Premium, which I understand is supposed to be able to write into Excel. Specifically, I would like Copilot to summarize text information from one column, summarize it with a keyword, and write this into corresponding cells in an adjacent column. Everything I have read shows that my version of Copilot should do this, and I've even seen tutorials doing so, but Copilot tells me that it cannot. Additionally, the formulas that Copilot generates that are supposed to do this will not work. Does anyone have advice or help on what is going wrong? Thanks in advance!

Answer 1

Copilot in Excel can write into workbooks, but only when specific product, file, and data conditions are met. Several limitations in the current experience likely explain why Copilot says it cannot perform the operation and why generated formulas fail.

Key points and checks:

1. Confirm the right Excel and Copilot experience

• Copilot in Excel supports generating formulas, summarizing data, and adding columns/rows, but some older “App Skills” features (including certain formula-generation flows) are being deprecated and replaced by Agent Mode, Copilot Chat, and Analyst.
• If a tutorial shows the older App Skills pane or specific “Suggest a formula column” UI, that exact flow may no longer be available or may behave differently. The current guidance is to use:
  • Agent Mode in Excel to generate formulas and edit the workbook.
  • Copilot Chat in Excel to ask questions and request transformations.
  • Analyst for deep reasoning data analysis.
  References for these changes:
  • The “Generate formula rows and columns with Copilot in Excel” and “Generate single-cell formulas with Copilot in Excel” features are explicitly marked as being deprecated and replaced by these newer experiences.

2. Ensure the workbook and data meet Copilot requirements Copilot in Excel only works on supported files and data formats:

• File type and location:
  • Must be an Excel file (.xlsx, .xlsb, or .xlsm).
  • Must be saved to OneDrive or Microsoft 365 SharePoint with AutoSave turned on.
• Data format:
  • Data should be formatted as a table or supported range. If the column to summarize is just loose cells, convert it to a table first (Home → Format as Table) so Copilot can reliably reference it.
• Sensitivity label:
  • The workbook’s sensitivity level must not be set to Confidential or Highly Confidential for certain Copilot actions, including formula generation, to work.

If any of these conditions are not met, Copilot may respond that it cannot perform the requested write operation or may fail to generate usable formulas.

3. Use the supported Copilot flows for writing into Excel For adding a summarized keyword into an adjacent column, use the supported Copilot experiences:

A. Generate formulas in columns/rows (where still available)

1. Open Excel and ensure the data is in a formatted table.
2. From the Home tab, select Copilot.
3. In the Copilot pane, choose “Suggest a formula column” or “Show suggestions for formula columns.”
4. Prompt in natural language, for example: “Add a column that summarizes the text in [ColumnName] into a single keyword for each row.”
5. Review the suggested formula and explanation, then select Insert column.

B. Use Agent Mode or Copilot Chat (if the above is deprecated in the tenant)

• Open Copilot in Excel (Agent Mode or Copilot Chat, depending on what is available in the ribbon).
• Clearly specify the table and columns, for example: “In Table1, summarize the text in the Description column into a single keyword and write it into a new column called ‘Keyword’.”
• Copilot should either:
  • Directly add the column and fill values, or
  • Propose a formula that can be inserted.

4. Why Copilot-generated formulas might not work Even when Copilot generates formulas, they may fail if:

• Column or table names in the formula do not match the actual names in the workbook.
• The data is not in a table, but the formula uses structured references (e.g., Table1[Description]).
• The formula uses functions not available in the current Excel build.

Because Copilot can generate inaccurate or inappropriate content, including formulas, it is necessary to:

• Check that the formula references the correct table and column names.
• Adjust the formula to match the actual structure of the workbook.
• Test the formula on a few rows before applying it to the entire column.

5. General Copilot reliability and expectations

• Copilot’s insights, formulas, and tables are a starting point and can be inaccurate. All generated content should be reviewed, edited, and verified.
• Some features are still rolling out and may not yet be available in all tenants or builds, even if documentation or tutorials show them.

If all of the following are true:

• The workbook is a supported file type in OneDrive/SharePoint with AutoSave on.
• Data is formatted as a table.
• Sensitivity is not Confidential/Highly Confidential.
• The tenant has the current Copilot in Excel experiences (Agent Mode/Copilot Chat/Analyst).

Then Copilot should be able to either directly write the summarized keywords into a new column or provide a working formula after minor adjustments to match the workbook’s structure.

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References:

• Frequently asked questions about Copilot in Excel
• Generate formula rows and columns with Copilot in Excel
• Generate single-cell formulas with Copilot in Excel
• Use Copilot in Excel with a screen reader
• Understand formulas with Copilot in Excel
• Get started with Copilot Pro