Requirement: To Provide a SharePoint document library permissions, SharePoint Administrator or SharePoint site owner, can change the permission, so that the correct people can able access the data that they need to access in the SharePoint document library.
- In SharePoint by default, all sites, and list libraries in a site collection inherit the permissions which are directly above them in the SharePoint site hierarchy. This means a SharePoint site can inherit the permission from the source site and a SharePoint Subsite can inherit the permission from the parent site.
- In SharePoint, neither we can break permission inheritance on the library itself nor we can re-inherit the permission on the library itself.
- If we want to assign unique permission to a SharePoint document library, we have to first break the permission inheritance and then only we can assign unique permission to the document library.
How to assign unique permissions to a SharePoint Online document library
- Now, see how can assign unique permissions to a SharePoint Online document library.
- To achieve this, initially, need to break the permission of the SharePoint document library. By default, it will inherit the permission from the parent site.
Process to break permission inheritance in the modern SharePoint Online document library,
- Open the SharePoint Online document library for which is to break the inherit permission, Select the settings gear icon, and click on Library Settings.

SharePoint Online document library settings
In the Library settings page, Under Permissions and Management select the Permission for this document library option.

SharePoint Online document library permissions
Now to break permission inheritance from the parent site, under the Permissions tab, Choose the Stop Inheriting Permissions.
Once you break permission inheritance for the SharePoint list, you can assign unique permission or grant permission to the new user, and the modern SharePoint online library.

break permission inheritance in the SharePoint Online document library
In the pop-up box, click on the Ok button. Any changes made in the parent site permission will not affect the SharePoint document library.

break permission inheritance in the SharePoint document library
Once you break permission inheritance, we can see options to grant, modify, remove and check permission in the modern SharePoint Online document library, under the Permissions
break permission inheritance in SharePoint document library, this is the process of break permissions SharePoint online document library.
Now Assign Unique permissions to the SharePoint Online document library
Make sure stop the inheritance permission for the document library, can assign unique permissions to the modern SharePoint document library.
- Open the SharePoint Online document library-> Select the settings gear icon -> click on the Library Settings.
- On the Library setting page, Under Permissions and Management select the Permission for this document library option.
- To assign unique permission, select the Grant Permissions option under the Permissions tab. If unable to see the Grant permission option then the document library is still inheriting permissions from the parent site.

Assign unique permissions in the SharePoint Online document library
Now, In the dialogue box, invite the user by entering the email address or name to the SharePoint Online document library.
Can also have an option to send an invite message which is an optional field.
Once click on the Show Options, see another two options to send an email invitation and to choose the Permission level for the specified user.
Now send an email invitation to the selected user, can check the checkbox else uncheck it.
Set the permission level for the user to access the SharePoint Online document library.
- By default, the edit permission level is granted for the users, also change the permission level as mentioned below:
- Full Control – Users have full control to access the SharePoint document library, they can even add and delete members to the site.
- Design – Users can create new document libraries, columns, and views, and also they can customize the layouts.
- Edit – Users can add, view, edit and delete the SharePoint document library, and also they can add, view, update and delete the SharePoint document library items.
- Contribute – Users can add, view, update and delete the SharePoint document library.
- Read – Users can only download documents and view the document library, they cannot able to edit the SharePoint document library

Assign unique permissions to the SharePoint Online document library
- Click on the Share button to send the invitation to the selected users like below.
The Shared User is added with the assigned permissions under the Permissions tab.

Assign unique permissions to the SharePoint Online document library