Not able to change Sharepoint site from private to public (statusCode='400(BadRequest)

For a normal Microsoft 365 group-connected team site, change the privacy through Settings → Site information → Privacy settings → Public → Save; if that returns HTTP 400, check whether a sensitivity label locks the site to Private before using the administrative group fallback.

1. Check for a sensitivity-label lock

A sensitivity label configured with Privacy = Private overrides the existing privacy setting and locks it. The site cannot be changed to Public until the label is removed or replaced with a label configured as Public or None.^1^

1. Open the site and select Settings → Site information.
2. Check the Sensitivity value.
3. If a label is applied, review its container privacy configuration in Microsoft Purview:
   • Public permits anyone in the organization to access the site.
   • Private locks it to approved members.
   • None leaves owners able to choose the privacy setting.
4. Remove the restrictive label or apply an approved label configured as Public or None.
5. Return to Settings → Site information, select Public, and save.

For a group-connected site, a Microsoft 365 group owner can change the label; for a site that is not group-connected, a SharePoint site administrator is required.^1^

2. Confirm that the site supports Public/Private privacy

The Public/Private selector applies to team sites. Public means anyone inside the organization can access the site; it does not make the site publicly accessible on the internet.^2^

Check the site’s origin:

• Standard group-connected team site: It supports changing the privacy setting.
• Communication site or nongroup-connected site: Manage access through SharePoint permissions rather than Microsoft 365 group privacy.
• Teams private-channel site: It cannot be made public independently. Membership and permissions are synchronized from the private channel, and private channels cannot be converted to another channel type.^3^

For a supported group-connected site, the documented site path is Settings → Site information.^4^

3. Use Exchange Online PowerShell as the administrative fallback

If this is a group-connected team site, no restrictive sensitivity label is applied, and the UI still returns 400, an administrator with the required Exchange Online permissions can update the associated Microsoft 365 group directly. AccessType accepts Public and Private.^5^

# Connect using an account with the required Exchange permissions.
Connect-ExchangeOnline

$group = "[Email]"
Set-UnifiedGroup -Identity $group -AccessType Public

Get-UnifiedGroup -Identity $group |
    Select-Object DisplayName, AccessType

The expected result is AccessType : Public. Then reopen the SharePoint site and check Settings → Site information.

4. Check ownership and escalate if necessary

The operation requires appropriate owner or administrative permissions. A SharePoint administrator can inspect and update ownership under:

1. SharePoint admin center → Sites → Active sites
2. Select the site.
3. Select Membership.
4. Verify that the intended account is a group owner or site administrator.^6^

If both the UI and Set-UnifiedGroup fail after confirming the site type and label configuration, open a Microsoft 365 support request and include:

• The UTC timestamp of the failed attempt
• Site URL and site type
• Whether a sensitivity label is applied
• The full error response
• Request ID [GUID]

A 400 response alone indicates that the service rejected the request; it does not identify which policy or site condition caused the rejection.

References

1. Use sensitivity labels to protect collaborative workspaces (groups and sites)
2. Office 2019 - 2021 and Web (#tab/office-2019-2021-and-web)
3. IT Admins - Private channels in Microsoft Teams
4. Default SharePoint groups
5. Set-UnifiedGroup-Description
6. Manage site admins