Excel: The File Format and Extension of Don’t Match [FIXED]

You may need to rename the file so that the extension matches the actual format of the file ✅

4 min. read

Updated onOctober 2, 2024

updated onOctober 2, 2024

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Key notes

On the Microsoft support forum, some Excel users have discussed an error message that states:The file format and extension of ‘file.xls’ don’t match. The file could be corrupted or unsafe. Unless you trust its source, don’t open it. Do you want to open it anyway?

Users can then select to open the Excel file. However, users have said that their spreadsheet files have lost all their data when they clickYesto open. If you need to fix that same error, check out some of the resolutions for it below.

What does it mean when a file format and extension don’t match?

When a file’s format and extension do not match,it means that the file has been saved in a format that is different from the extension that has been given to it.

For example, if a file has been saved as an Excel spreadsheet, but it has been given the “.txt” extension, it means that the file has been saved as a text file instead of an Excel spreadsheet.

This can cause problems when you try to open the file, because Excel may not recognize the file’s true format and may not be able to open it correctly. You may also get theextension is not valid errorwhen you open the Excel file.

It is important to ensure that the file format and extension match, so that you can open and use the file correctly in Excel.

How do I fix the file format and extension don’t match?

1. Change the file’s extension (worked for most users ✅)

2. Select the Open and Repair option

3. Unblock the Excel file

4. Turn off Protected View

5. Open the file in LibreOffice Calc

You can also try opening the Excel file the error arises for inLibreOffice Calc. That’s a freeware spreadsheet application you can add to Windows by clickingDownloadon theDownload LibreOffice page. Then install Calc’s office suite with the downloaded setup wizard.

When you try opening the file inLibreOffice Calc, the application might ask you to select an appropriate format. Select alternative formats until you get the file opened. Thereafter, you can copy and paste all the data in the spreadsheet into a blank Excel sheet with theCtrl+CandCtrl+Vkeyboard shortcuts.

Those are some of the confirmed resolutions that users have fixed Excel’sfile format does not match extensionerror with.

If the file the issue arises for is not from a trusted source, however, do not select to open it. Instead, scan the file with an antivirus utility before trying to open it.

Excel: The File Format and Extension of Don’t Match [FIXED]#

What does it mean when a file format and extension don’t match?#

How do I fix the file format and extension don’t match?#

1. Change the file’s extension (worked for most users ✅)#

2. Select the Open and Repair option#

3. Unblock the Excel file#

4. Turn off Protected View#

5. Open the file in LibreOffice Calc#