Entra account whose UserType is Guest, created when a B2B invitation is accepted; its UPN takes the #EXT# form, but that is not what the person signs in with.
Read more: Microsoft Learn
In the Ultra Transcenders books
Each book explains Guest user in context, with comparison tables and the common traps.
Terms in this definition
- UserType
A property on Microsoft Entra users, set to Member or Guest, describing how the person relates to the organisation. It says nothing about their sign-in method or their roles.
- B2B
Business-to-business features in Microsoft Entra External ID for working alongside partner organisations. Direct connect lets people share Teams channels with no guest account needed, whereas collaboration brings partners into your tenant as guests.
- UPN
User principal name, the user@domain sign-in name of a user. Only domain suffixes verified in the tenant can be used.