Expert guide

Excel Co-Authoring Not Working? Fix 'Locked for Editing'

What co-authoring needs, why it fails, and when a shared spreadsheet has outgrown itself

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Short answer: co-authoring works only when the file is in OneDrive, SharePoint or Teams, saved as .xlsx, .xlsm or .xlsb, opened in Microsoft 365 Excel or Excel for the web with AutoSave on, and not using the legacy Shared Workbook feature, password encryption or other blocking features. Make everyone open it from the cloud location (not a network drive or an emailed copy), turn off legacy sharing, and use Version History to recover from conflicts. If many people edit structured records all day, the workbook should probably be a database; see Excel to database solutions.

"Sarah has it open" is the most common reason work stops in a spreadsheet-based team. Microsoft 365 co-authoring was meant to end that, and in the right conditions it does: several people edit at once and see each other's changes within seconds. When any one condition is missing, the second person gets a read-only copy, a lock message, or a merge conflict later.

Co-Authoring Requirements Checklist

RequirementCheck
LocationOneDrive for Business, SharePoint Online or Teams files (not a network drive, not email)
Format.xlsx, .xlsm or .xlsb (not .xls, not .csv)
Excel versionMicrosoft 365 desktop, Excel for the web, or mobile apps; older perpetual versions cannot co-author
AutoSaveOn (top-left toggle) when opened in desktop Excel
Legacy Shared WorkbookOff (Review → Share Workbook (Legacy))
EncryptionNo 'Encrypt with Password'; use sensitivity labels or permissions instead

'Locked for Editing by Another User'

  • File is on a network share

    Network files only allow one editor. Move the file to SharePoint or OneDrive.

  • Someone uses an older Excel

    Excel 2016/2019 perpetual opens the file exclusively. Ask them to use Excel for the web, or upgrade.

  • Opened from a synced folder with AutoSave off

    Turn AutoSave on, or open from the SharePoint site with Open in Desktop App.

  • A stale lock

    After a crash, a lock can persist briefly. Wait a few minutes or ask the person to close Excel completely.

  • Blocking features

    Legacy Shared Workbook, password encryption, or (in some older builds) certain legacy features prevent co-authoring.

Upload Failed and Merge Conflicts

These come from the OneDrive sync client rather than Excel itself. They occur when a local copy changed while offline, or when two incompatible clients edited the same file. To recover, open the file's Version History in SharePoint or OneDrive, compare versions, and restore or copy across the missing changes. To prevent them, discourage working on downloaded copies and keep AutoSave on.

Workbook Design for Several Editors

  • Give each person or team their own sheet or table area for input, and summarise on a separate sheet.

  • Avoid macros that restructure sheets (insert columns, sort everything) while others are editing.

  • Use Excel Tables for input so new rows extend cleanly.

  • Use Sheet Views (View → Sheet View) so filters and sorts are personal and do not disturb others.

  • Protect formula areas so collaborators cannot overwrite them by accident.

Macros and Co-Authoring

Desktop Excel for Microsoft 365 can co-author .xlsm files, but macros do not run in Excel for the web, and macros that rewrite large areas create conflicts. Run such macros when others are out of the file, or move automation to Office Scripts, which run in the cloud version; see Office Scripts vs VBA.

When a Shared Workbook Has Outgrown Itself

SignWhat it means
More than a handful of people entering records all dayYou need a multi-user database with forms
Frequent overwrites and 'who changed this?'You need record-level history and permissions
Different people should see different rowsYou need row-level security
Tens of thousands of rows and slow AutoSaveThe data has outgrown a workbook
Copies emailed around to avoid lockingThe process needs a single source of truth

The usual next steps are an Access front end with a shared back end for an office team, a SQL Server or Dataverse back end with Power Apps for broader access, or a web application. See converting Excel to Access, Excel vs Airtable vs Smartsheet and Excel to database solutions. For tracking who changed what in the meantime, read our Excel and Access audit log guide.

FAQ

Excel co-authoring FAQ

Locks, conflicts and shared workbooks

Real-time co-authoring needs the workbook stored in OneDrive, SharePoint or Teams, opened with a Microsoft 365 version of Excel or Excel for the web, with AutoSave on, in a supported format (.xlsx, .xlsm or .xlsb). Files on network drives, files using the legacy Shared Workbook feature, or encrypted files open as read-only or 'locked for editing' for the second user.

Excel could not open the file for co-authoring, so the first person to open it holds an exclusive lock. On a network share this is normal. In SharePoint or OneDrive it usually means someone opened it with an older Excel version, from a synced local copy without AutoSave, or the file has a feature that blocks co-authoring.

No. The legacy Shared Workbook feature is outdated, disables many Excel features and is incompatible with co-authoring. Turn it off and use co-authoring in OneDrive or SharePoint instead.

Sync conflicts happen when the OneDrive client cannot merge changes, often because someone edited a local copy while offline, or two people used versions of Excel that cannot co-author. Use Version History to compare and recover, and make sure everyone opens the file from SharePoint with AutoSave on.

Macro-enabled .xlsm files can be co-authored in desktop Excel for Microsoft 365, but macros do not run in Excel for the web, and macros that make heavy structural changes can cause conflicts. Keep macro-driven processes to one person at a time or move them to Office Scripts.