# Work on the same Word, Excel or PowerPoint file together > Save the file to OneDrive or SharePoint, share it with edit access, and several colleagues can work in it at the same time, with comments and @mentions. > > Source: https://docs.officeniaga.com/m365-office-coauthoring/ To work on a file with colleagues at the same time, save it in OneDrive or on a SharePoint team site, then share it with **Can edit** access. Everyone who opens it sees each other's changes within seconds, with no need to email copies back and forth. ## What you need Co-authoring works when these are true: - **The file is in the cloud**: saved in OneDrive or on a SharePoint site, not on your computer's hard disk or a USB drive. - **The file is in a modern format**: `.docx`, `.xlsx` or `.pptx`. Older formats such as `.doc` and `.xls` do not support it; open the file and save it in the newer format first. - **Everyone has edit permission** to the file. - **AutoSave is on** in the desktop apps. See [AutoSave and version history](/m365-office-autosave-versions/). ## Share the file for editing You can share straight from Word, Excel or PowerPoint. 1. Open the file and select **Share** at the top right. In the web apps, **Share** opens a small menu: select **Share** again. *(Screenshot: Word for the web with the Share menu open and Share highlighted)* 2. Type the names or email addresses of your colleagues in **Add a name, group, or email**. 3. Check the permission next to the box is **Can edit** (the pencil icon). 4. Select **Send**. Or select **Copy link** to paste the link into a Teams chat. The share box works the same as in OneDrive. See [share a OneDrive file](/m365-onedrive-share/) for the permission and link options. ## Work together Each person can open the file in the desktop app, the web app or the phone app. Pictures or initials at the top right show who else is in the file, and a coloured marker shows where each person is working. Changes appear as people type. On a phone, open the file from the OneDrive or Microsoft Copilot app. It opens to read first; tap **Edit** at the bottom right to change it. On Android, if the Word, Excel or PowerPoint app is not on your phone yet, Google Play opens so you can install it. *(Screenshot: On Android: a sample Word file open to read in the Microsoft Copilot app, with the Edit button highlighted)* If you open the file in the browser and want the full desktop features, select **Editing** at the top right, then **Open in Desktop**. The same menu switches between **Editing**, **Reviewing** (suggest changes only) and **Viewing**. *(Screenshot: Editing menu in Word for the web with Open in Desktop highlighted)* ## Leave comments and @mention people Comments are a tidy way to ask questions without changing the text. 1. Select the text or cell, then go to **Review** > **New Comment**. A comment box opens on the right. *(Screenshot: Word for the web Review tab with New Comment highlighted and an empty comment box)* 2. Type your comment. To notify someone, type **@** and start typing their name, then pick them from the list; they get an email with a link to the comment. 3. Select **Comment**, or press **Ctrl+Enter**. In the desktop apps, the button is the **Post comment** arrow. *(Screenshot: Comment box with a sample question and the Comment button highlighted)* The comment then shows next to the text with your name and the time. Colleagues can answer in **@mention or reply** under it. *(Screenshot: Posted comment in Word for the web with the @mention or reply box underneath)* In Word and Excel you can also tick **Assign to** under an @mention to give the person a task. ## If two people change the same thing When two people edit the same sentence or cell at the same moment, the last change saved is the one kept. For important sections, agree who edits what, or use comments. You can always get an earlier version back from [version history](/m365-office-autosave-versions/). ## Still stuck WhatsApp our support team at [+60 16-916 3324](https://wa.me/60169163324). ## Common issues ### Excel says the file is locked for editing by another user. Someone has the file open in an app or version that cannot co-author, or the file is in an old format such as .xls. Ask them to close it, and save the file as .xlsx in OneDrive or SharePoint. ### I cannot see my colleague's changes. Check that AutoSave is on at the top left, select Enable Editing if you see a yellow bar, and make sure OneDrive sync is not paused. ### Can I co-author a file sent to me as an email attachment? No. An attachment is a separate copy. Save the file to OneDrive or a team site and share a link instead.