Forum Discussion

careercargo's avatar
careercargo
Copper Contributor
Oct 23, 2026

Copilot Notebook Sees 78 Files but Only Accesses About 20. Why?

I'm looking for a definitive technical answer from Microsoft, not guesses or workarounds. I'm testing Copilot Notebooks with a folder stored in OneDrive (in Australia). The notebook interface clearl...
sapanpatel's avatar
sapanpatel
Copper Contributor
Oct 23, 2026

Hi,

I checked Microsoft's documentation on Copilot Notebooks. Here are a few things worth investigating.

  1. Check the reference limits

Microsoft documents different reference limits depending on your license:

  • Microsoft 365 Copilot users can add more than 300 references, but only the first 300 are used for grounding.
  • Copilot Chat users can add up to 50 references.

Since your notebook contains 78 files, this does not appear to be a documented 20-file limit.

Official documentation:
https://support.microsoft.com/en-us/microsoft-365-copilot/add-references-to-your-microsoft-365-copilot-notebook

  1. Check whether Copilot can read individual files

Seeing 78 files listed does not necessarily mean Copilot retrieves content from every file for every question. It selects relevant information based on your prompt.

Try asking Copilot to summarize a specific document by its exact filename. Test this with a Word document, a PDF, and an Excel workbook.

If individual files work but broader questions only use some sources, the issue may be related to content retrieval or relevance.

  1. Check file formats, permissions, and folder references

Confirm that the files use supported formats and that you can open them directly. Also, try adding one problematic file individually instead of relying only on the folder reference.

Microsoft's documentation explains how Copilot Notebooks uses references:
https://support.microsoft.com/en-us/microsoft-365-copilot/how-microsoft-365-copilot-notebooks-works

My conclusion:

I couldn't find official Microsoft documentation confirming a 20-file retrieval limit for Copilot Notebooks. If the issue persists, report it through the Microsoft 365 Copilot feedback mechanism and include your license type, file formats, and a reproducible example.

One question that could help narrow this down: Are you using Microsoft 365 Copilot Notebooks with a work or school account, or Copilot Chat?

If this helps, please like the response.

Connect with me on LinkedIn:
https://www.linkedin.com/in/sapan-patel-807321222/