Customer numbers that appear twice in the list, dates in three notations, and numbers that Excel has stored as text: the Copilot skill clean-data looks for errors like these. Since October, Microsoft has been gradually rolling it out to all users of Copilot in Excel on Windows, on the Mac, and on the web, as the Excel overview for October reports.
The skill explains each finding and suggests the correction directly in the workbook. Only what you select individually is applied.
Which errors does clean-data find?
Microsoft names five types of errors that can distort formulas, lookup functions such as VLOOKUP, PivotTables, and reports:
superfluous spaces
inconsistent text and number formats
dates in different notations
duplicate values
values with the wrong data type, such as numbers in text format
As an example, Microsoft cites a column in which the same country appears once as USA, once as US, and once as United States. A PivotTable counts three different countries from this. You can call up the skill with @clean-data in the prompt or via the Skills menu in the Copilot pane. In the "Manage plug-ins & skills" dialog, it is located in the "Data and analysis" folder and is enabled by default.
Who gets the new features?
Copilot in Excel requires one of these subscriptions:
Microsoft 365 Personal or Family with AI credits
Microsoft 365 Premium
a Microsoft Copilot for business subscription
a Business or Enterprise subscription of Microsoft 365 or Office 365 that includes Copilot Chat
The help page notes that the skill has not yet arrived in every account. In addition, usage limits apply, which depend on server capacity and may change. Copilot in Excel understands German prompts; Microsoft does not mention a regional restriction for the skills. The other new features of the month do not reach all platforms at the same time:
Feature
Where
Status
Skill Builder: save your own workflows as a skill
Windows, Mac, Web
Rollout to everyone in progress
Skill Recorder: Copilot records your work steps as a skill
Web, Windows, Mac
on the web for everyone, on Windows and Mac only in the Insider program
Get Data: fetch data via prompt, result as a Power Query query
Web only
available
Interactive reports from workbook data (interactive canvas)
Windows
only in the Insider program
Name tables when creating them, without Copilot
Windows
for everyone
What changes without Copilot?
In the "Create Table" dialog in Excel for Windows, you can now enter a name right away, regardless of whether you open it with Ctrl + T or via Insert › Table. Previously, every new table was initially called Table1, Table2, and so on, until you renamed it under Table Design. The name appears in every formula with a structured reference: =SUM(Invoices[Amount]) is easier to read than =SUM(Table3[Amount]). In September, the feature was only open to participants in the Insider program.
What this means for you
It's best to first check in the settings of your Microsoft 365 account which subscription you have. With Microsoft 365 Personal or Family without AI credits, the Copilot button is missing in Excel.
First run clean-data on a copy of your list and go through each suggestion before you continue working with the data. Copilot only edits workbooks with automatic calculation; if your file is set to manual, change that under Formulas › Calculation Options. How to analyze the cleaned list afterwards is shown in the course on PivotTables in Excel.
It's best to name new tables right when you create them; in long formulas you can then see at a glance which list is meant, instead of having to decipher Table3. An overview of Copilot in Word, Excel, and PowerPoint is provided by the video training on Microsoft Copilot.
Microsoft published the Excel overview for October on October 27, 2026.
