Allow External User to Open in Desktop App

[Shawn Keene]

I have O365 business, and I shared an Excel file with an external user (not in our AAD/domain).

They can open the Excel file in their browser with Excel Online, but the "open in desktop app" doesn't show up for them.

Is there a setting I can change to allow this external user to open the file in the full Excel program?

[#2]

this is actually a Sharepoint question. When you share the link to the excel file there are different options available to make the link read-only, make it edittable, and for internal and external users. You need to change the link settings/permissions in Sharepoint.

[#3]

Appreciate the reply. I found a thread that lists out the details: https://techcommunity.microsoft.com/t5/sharepoint/external-users-can-t-open-documents-in-desktop-app...

That includes some direct responses from Microsoft indicating how it works (and unfortunately how it won't work for me).

[#4]

@Shawn Keene To allow "Open in Desktop" functionality, you need to add the person you are collaborating with as a Guest in your Azure Directory. Follow these steps: https://docs.microsoft.com/en-us/azure/active-directory/external-identities/b2b-quickstart-add-guest... 

Once your Guest is added, go to the file or folder you would like to share, and enter the Guest email address.

Note: In order for it to work, make sure your org settings allow sharing with guests: https://docs.microsoft.com/en-us/sharepoint/turn-external-sharing-on-or-off 

If this worked for you, please give it a thumbs up.