About this article
This article is created using an automated generation workflow leveraging generative AI. Based on official Microsoft information, it outlines practical procedures for checking files in the order of 'structure -> missing values -> types -> aggregation -> visualization' rather than immediately asking for conclusions when passing Excel files to Copilot Chat.Verification Status: 📘 Official Microsoft information confirmed, live tenant unverified
Information Verification Date: October 5, 2026
If you pass an Excel file to AI and ask it all at once to 'analyze these sales,' the results may come back quickly, but it becomes difficult to check which rows were excluded or whether there were values that could not be read numerically.
In Copilot Chat,checking the data structure first and then proceeding to analysismakes verification much easier.
- Is this allowed under your contract?
- Verify the structure using dummy Excel data
- Next, check for missing values
- Check for data type inconsistencies
- Output the "number of excluded rows" during aggregation as well
- Check the summary table before the chart
- Change only one condition at a time
- Where do uploaded files go?
- Distinguish from Copilot in Excel
- Metrics to measure in the pilot
- Items to be verified by administrators
- Official Information
Is this allowed under your contract?
According to official Microsoft information as of October 5, 2026, Copilot Chat is available for organizations with eligible Microsoft 365 / Office 365 subscriptions, allowing users to upload Excel files to chat and request analysis or visualization.
| Objective | Main conditions |
|---|---|
| Upload Excel to Copilot Chat | Eligible Microsoft 365 subscription + Entra ID + Copilot Chat |
| Ask questions about the uploaded file | Within Copilot Chat standard access and upload limits |
| Built-in Copilot within the Excel application | Verify conditions such as Microsoft Copilot licensing |
| Work-based chat leveraging organizational data broadly | Check the license requirements for Microsoft Copilot |
| Agents using shared tenant data such as SharePoint | Check the licensing or consumption-based billing conditions |
The feature to upload Excel files to Copilot Chat and the Copilot feature within the Excel application do not share the same licensing boundary.
Verify the structure using dummy Excel data
Start by testing with a dummy table like the following instead of real data.
| Date | Department | Sales | Representative |
|---|---|---|---|
| 10/1/2026 | Sales A | 120000 | Aoki |
| 10/2/2026 | Sales B | 85000 | Ito |
| 10/3/2026 | Sales A | Sato | |
| 10/04/2026 | Sales B | 90,000 JPY | Takahashi |
The first question is not analysis.
このExcelを分析する前に、データ構造だけ確認してください。 - シート名 - 列名 - 行数 - 空欄がある列 - 数値として扱えない可能性がある値 - 日付列 - 重複の可能性 まだ売上や傾向について結論を出さないでください。
At this point, a person opens the actual Excel file and verifies whether the sheet names, column names, and row counts match.
Next, check for missing values
空欄を含む列を一覧にしてください。 各列について、 - 空欄件数 - 全体に占める割合 - 分析時に注意する理由 を表示してください。 勝手に値を補完しないでください。
Whether blank spaces are automatically replaced with 0 or imputed with the average value alters the meaning depending on the analysis purpose.
Therefore, "finding missing values" and "deciding how to handle missing values" are treated as separate steps.
flowchart LR
A["Excelアップロード"] --> B["構造確認"]
B --> C["欠損確認"]
C --> D["型確認"]
D --> E["集計"]
E --> F["人が照合"]
F --> G["可視化・考察"]
Check for data type inconsistencies
In the sales column,
120000 85000 空欄 90,000円
if mixed in, it does not necessarily mean all values can simply be summed up as numeric data.
Specify the conditions as follows.
売上列について、 数値として扱える値と扱えない可能性がある値を分けてください。 まだ文字列を数値へ自動変換しないでください。 変換候補がある場合は、元の値と候補値を並べてください。
If the AI automatically cleans the data before analysis, it becomes difficult to see what corrections were made.
Output the "number of excluded rows" during aggregation as well
After checking the data types,
売上金額を数値として確認できた行だけを対象に、 部署別の件数と合計を整理してください。 集計対象から除外した行数と、 除外理由も表示してください。
set as follows.
In addition to the total value,How many items were excluded from the calculationwill be displayed together.
Check the summary table before the chart
月別売上を集計してください。 グラフを作る前に、 月と合計値の表を表示してください。
While charts are easy to understand visually, even an incorrect aggregation can look plausible.
Display the table first, verify the numbers against the source data or PivotTable, and then proceed to visualization.
Change only one condition at a time
Initially, it was broken down by department.
Next, we will use
部署別ではなく担当者別にしてください。 それ以外の集計条件と除外ルールは変えないでください。
.
Instead of changing multiple conditions at once, changing them one by one makes it easier to trace the differences in the results.
Where do uploaded files go?
According to the Microsoft Copilot Chat FAQ, uploaded files are saved to the user's OneDrive for Business and can be deleted by the user.
Furthermore, under Enterprise Data Protection, it is explained that uploaded files are not used for model training.
However, when used in a corporate environment, additional considerations include
confidentiality classification
DLP
personal information
customer data
retention policy
OneDrive sharing settings
Check AI usage rules.
Review these.
"Not being used for model training" and "permitted to be uploaded under internal regulations" do not mean the same thing.
Distinguish from Copilot in Excel
Understand the method of passing Excel files to Copilot Chat separately from the feature of using Copilot alongside cells or tables in the Excel app.
According to official Microsoft licensing documentation, there are differences between the web-based Copilot Chat included in applicable agreements and the work-based chat or in-app Microsoft 365 features provided through the Microsoft Copilot license.
When explaining within a company,
"Copilot is available"
is not enough;
"which Copilot interface, what data, and under what contract terms can be used"
must be explicitly documented.
Metrics to measure in the pilot
Measuring the following during Excel analysis makes it easier to compare practical effectiveness.
| Metric | Verification example |
|---|---|
| Structure verification time | How many minutes it took to check columns, rows, and missing values |
| Aggregation creation time | Comparison with manual work or PivotTable |
| Number of incorrect aggregations | Errors found through manual verification |
| Clarity of exclusion reasons | Which rows were excluded and why |
| Correction time | Time spent by humans correcting Copilot output |
| Total working time | AI response + human verification and correction |
Evaluation is based on the total time including human review, rather than just the AI response speed.
Items to be verified by administrators
Before enterprise deployment,
Target licenses
Entra ID account
Copilot Chat usage settings
Web search settings
File upload restrictions
Saving to OneDrive for Business
Purview / DLP / sensitivity labels
Functional differences with additional Microsoft Copilot licenses
Status of phased rollout within the tenant
will be verified.
