If your organization performs work that involves sharing documents with customers or collaborating with partners or vendors, you'll want to allow external sharing in OneDrive for Business. To help protect sensitive information, you might also want to limit sharing with people outside your organization.
External sharing, including anonymous access links, is turned on by default for your entire organization and the site collections in it, including OneDrive.
Control external sharing for OneDrive
Because OneDrive is a site collection within SharePoint Online, your organization's SharePoint Online settings determine which OneDrive sharing settings are available. Keep the following in mind as you configure sharing for OneDrive.
The external sharing setting for OneDrive can be more restrictive than what's allowed for SharePoint Online, but not less restrictive. If you turn off external sharing for SharePoint Online in your organization, you can't turn it on for OneDrive. If you limit external sharing in SharePoint Online, to only authenticated users, then that will be the only kind of external sharing you can allow in OneDrive. If you allow anonymous access links for SharePoint Online, you can limit external sharing in OneDrive to authenticated users or turn it off entirely.
If external sharing is turned off globally in the SharePoint Online admin center, any shared links will stop working. If external sharing is later turned on, the links will resume working.
Open the OneDrive admin center, and click the Sharing tab.
Make sure the Let users share SharePoint files with external users setting is on, and note the Users can share with setting.
IMPORTANT: If you change this setting, it will affect all SharePoint site collections.
If you turn off external sharing for SharePoint, you can still change the detailed external sharing settings on the Sharing page. Your changes won't take effect until you turn on external sharing.
Turn on or off Let users share OneDrive files with external users.
If you want to:
Select this option:
For this result:
Allow sharing only for external users who are already in your Office 365 directory.
Only existing external users (sign-in required)
Users can only share with external users who already exist in your organization's directory (the external users have already accepted sharing invitations).
Require external users to sign-in with a Microsoft account or a work or school account before they can access shared files.
New and existing external users (sign-in required)
OneDrive users can share files with external users who sign in.
Invitations to view files can be redeemed only once. After an invitation has been accepted, it can't be shared or used by others to gain access.
Allow OneDrive users to share files with people who sign in, or to use anonymous access links, which do not require people to sign in.
Anyone, including anonymous users
Users can select to require sign-in for access to specific items they share. If they require sign-in, you can control whether external users are allowed to edit or share.
Anonymous access links let all recipients (including external users) view or edit shared files without signing in.
Anonymous access links can be forwarded to other people, who can also view or edit the shared items without signing in.
Set sharing limitations
After you select the main option for external sharing, you can refine your settings using these additional options on the Sharing page in the OneDrive admin center.
IMPORTANT: The following settings apply to both SharePoint Online and OneDrive. The settings you change in the OneDrive admin center sync with your settings in the SharePoint admin center.
Set a default link type
To better manage the type of links users share, you can set the default type of link that's created when users select Get a link to share files and folders.
OneDrive supports three types of links:
Direct links (accessible only by users who have specific permission to access the item)
Internal links (accessible only by users within your organization)
Anonymous access links (accessible by anyone with the link). This option is only available if your external sharing setting for SharePoint is set to Anyone, including anonymous users.
You may want to enable users to send anonymous access links (as these provide the smoothest experience) but you may not want it to be the default option when users open the Get a link dialog box. You can set the default type of link to something more restrictive, while still allowing users to select other types of links as needed.
Anonymous access link expiration and permissions
If your external sharing setting for SharePoint is set to allow anonymous access links (even if external sharing is currently turned off), you can set an expiration time for those links by choosing a value from the Links expire within drop-down list. You can also choose whether anonymous access links can give people permission to edit shared files and folders.
Limit external sharing using domains
You can allow or restrict access to specific domains.
What external users can do
You can choose what external users can do with the items that are shared with them with these options:
To help control the accounts external users use to access shared items, select the External users must accept sharing invitations using the same account that the invitations were sent to check box.
To allow external users to share items that other users have shared with them, select the Let external users share items they don't own check box. This setting is selected by default.