Excel says file is locked by another user

“I am the only one in the folder but Excel claims someone else has it open.”

Excel modal naming a lock owner with Read Only / Notify / Cancel buttons.

Likely cause

Excel or OneDrive left a lock file after a crash, sleep, or second Excel process. The named “other user” is often you on another device, or a leftover ~$ workbook in the same folder.

Confidence 85%Windows 11 · OneDrive / network share

1
Confirm you are not open elsewhere
Check other PCs, Excel Online browser tabs, and Excel processes in Task Manager. Close every copy of the workbook before deleting locks.
2
Clear the lock file on the share
In File Explorer show hidden items. In the workbook’s folder, delete the ~$YourFile.xlsx lock if it exists and nobody has the file open. Then reopen.
3
Release OneDrive / co-authoring
If the file lives in OneDrive or SharePoint, open the web version → … → Details and check who is editing. Sign out of stale sessions, then Open in Desktop app again.
4
Recover from autosave if needed
File → Open → Recover Unsaved Workbooks if the crash left edits only in autosave. Save As a new name, then replace the locked original once the lock is gone.

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