Restrict SharePoint Access with Custom Permissions

Typically, restricting SharePoint list permissions on the backend prevents users of Power Apps applications from accessing the data and making edits. This custom permissions tutorial will demonstrate two methods for securing a SharePoint backend without impacting Power Apps functionality.

Required: SharePoint site owner permissions

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The first custom permission level allows end users to make edits through the Power Apps application but will restrict users from accessing the SharePoint list by displaying an error message.

Click the drop-downs for step-by-step instructions.

Custom Permission Level #1

Step	Action
1	Within SharePoint, click the gear icon.
2	Select Site Permissions.
3	Click Advanced Permissions Settings.
4	Select Permission Levels from the permissions ribbon.
5	Click Add a Permissions Level.
6	Name the custom permission level.
7	Select the following options: List Permissions ·         Add Items ·         Edit Items ·         Delete Items ·         View Items ·         Open Items ·         View Versions ·         Delete Versions ·         Create Alerts Site Permissions ·         Browse Directories ·         Use Self Service Site Creation ·         View Pages ·         Browse User Information ·         Use Remote Interfaces ·         User Client Integration Features ·         Open ·         Edit Personal User Information   Personal Permissions ·         Manage Personal Views ·         Add/Remove Personal Web Parts ·         Update Personal Web Parts
8	Click Create.
9	Click the gear icon.
10	Select Site Contents.
11	Open a SharePoint list.
12	Click the gear icon.
13	Select List Settings.
14	Click Permissions for the List.
15	Click Stop Inheriting Permissions from the Permissions ribbon.
16	If there is a popup, click OK.
17	Click the checkbox next to the SharePoint group that requires the custom permissions.
18	Select Edit User Permissions from the Permissions ribbon.
19	Unselect existing permissions and then select the custom permissions.
20	Click OK.

The second custom permission level allows end users to change item-level permissions without being able to change any library settings.

Custom Permission Level #2

Step	Action
1	Within SharePoint, click the gear icon.
2	Select Site Permissions.
3	Click Advanced Permissions Settings.
4	Select Permission Levels from the permissions ribbon.
5	Click Add a Permissions Level.
6	Name the custom permission level.
7	Select the following options: List Permissions ·         Add Items ·         Edit Items ·         Delete Items ·         View Items ·         Open Items ·         View Versions ·         Delete Versions ·         Create Alerts   Site Permissions ·         Manage Permissions ·         Browse Directories ·         Use Self Service Site Creation ·         View Pages ·         Enumerate Permissions ·         Browse User Information ·         Use Remote Interfaces ·         User Client Integration Features ·         Open ·         Edit Personal User Information   Personal Permissions ·         Manage Personal Views ·         Add/Remove Personal Web Parts ·         Update Personal Web Parts
8	Click Create.
9	Click the gear icon.
10	Select Site Contents.
11	Open a SharePoint list.
12	Click the gear icon.
13	Select List Settings.
14	Click Permissions for the List.
15	Click Stop Inheriting Permissions from the Permissions ribbon.
16	If there is a popup, click OK.
17	Click the checkbox next to the SharePoint group that requires the custom permissions.
18	Select Edit User Permissions from the Permissions ribbon.
19	Unselect existing permissions and then select the custom permissions.
20	Click OK.

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Additional Resources

• General knowledge for hiding lists from SharePoint search and site contents (the list is only accessible through the URL).
• Remove the ability for members to change the list settings; it allows filters to be set and members cannot change the list settings. This method pairs well with the steps for custom permissions level #2.
• Information for utilizing power automate to add permissions to line items.