Microsoft Entra guest invites are one of those defaults that quietly create risk: by default, all users in your organization, including B2B guest users, can invite external users. If you assumed guest access stopped with the person you approved, it does not.
This guide is a useful admin PSA. It shows the exact setting in Entra ID to stop guests from inviting more guests, and for most tenants this is a sensible change to make now, not later.
What the guide gets right
The core point is simple: external collaboration should not run on autopilot. In Entra, go to Entra ID > External Identities > External collaboration settings and change Guest invite settings away from the most inclusive option.
The practical choice for many orgs is:
- Member users and users assigned to specific admin roles can invite guest users
If you want tighter control, use:
- Only users assigned to specific admin roles can invite guest users
That aligns much better with least privilege than giving every guest a path to create another guest.
The other part worth pairing with this is Guest user access restrictions. Microsoft documents that the default guest setting is only "limited" access, not fully locked down. Guests can still see some user properties and membership of non-hidden groups. If you are serious about zero trust, review whether guests should instead be restricted to their own directory objects only.
My verdict
This is the right advice, with one important caveat: turning off guest-to-guest invitations is necessary, but it is not enough.
The gotcha is that many teams think fixing the invite setting solves guest governance. It does not. Microsoft also notes that some Microsoft 365 experiences can still expose joined-group context, and external sharing behavior is spread across Entra, Teams, SharePoint and OneDrive. So if you built collaboration with loose assumptions, verify the full chain.
In practice, I would treat this change as the first five minutes of the job. The rest is governance:
- assign Guest Inviter instead of broad admin roles where possible
- run recurring guest access reviews if you have the licensing
- check cross-tenant access settings, not just external collaboration settings
- audit where direct sharing bypassed your intended process
That is exactly the kind of cleanup I usually include in an AI and automation audit, because identity sprawl tends to show up next to workflow sprawl.
The most useful takeaway
For most organizations, there is little downside to blocking guests from inviting more guests. If a business case exists, route it through named internal sponsors or a controlled process, or build that process properly with PowerShell or workflow automation.
If your environment depends on external collaboration at scale, this is also where more structured patterns such as Microsoft Copilot and AI agents or governed access packages start to matter: an agent should not get a blank check to your tenant, and neither should a guest.
Read the original for the exact click path and screenshots. It is short, accurate, and worth acting on.
