Large List and a Few Unique Item Permisions

Question

In a SharePoint Online list, what are the boundaries when it comes to breaking inheritance on a few list items?

The list has ~10k items.
At times, 50 items will need to have their permissions updated to allow for auditors to view them. Once the audit is complete, the list items will have their permissions reverted to inherit from the parent list.

The auditors belong to one SharePoint group and non-auditors belong to another group.

50 items have auditors and non-auditor permissions assigned to them. the remaining list items inherit from the parent list. would this equate to 2 uniquie permissions or 50+?

Answer 1

You can store up to 30 million items or files in a list or library.

When a list, library, or folder contains more than 100,000 items, you can't break permissions inheritance on the list, library, or folder. Nor can you re-inherit permissions on it. However, you can still break inheritance on the individual items within that list, library, or folder, up to the maximum number of unique permissions in the list or library .

For large lists, design to have as few unique permissions as possible and remain below 5,000 in total.

However, when a list view shows more than 5000 items, you may run into a list view threshold error.

Reference:

• SharePoint limits
• Manage large lists and libraries

Answer 2

Based on MS guidelines, breaking inheritance at the List, Library, Folder, and Individual item levels depends on the maximum number of unique permission allowed and also the item count at that level.

The item count limit at list, library and folder level is: 100,000

Unique Permissions allowed at the list and library level is: 50,000

The recommended unique permissions is: 5,000

Based on your requirements, I don't think you will have any issues.

Please visit the following articles for details

1. Customize Permissions Here
2. Breaking Inheritance Issue Resolution