Unknow guest named LAURENCE joined our meeting

Hi @Ghita,

Thank you for sharing your detailed concern regarding unknown users joining Microsoft Teams meetings.

In this situation, when a participant joins as an anonymous user, there is no way to retrieve their information such as email address or display name. However, as the meeting organizer, you can help prevent this issue by adjusting the meeting options.

To do so, please double‑click on the meeting in your Teams calendar and select Meeting options.

The first setting you will see is “Who can bypass the lobby?”. We recommend changing this from “Everyone” to a more restrictive option.

Updating this setting will either require external users to sign in before joining the meeting or prevent unknown users from bypassing the lobby entirely.

Please note that this configuration may be controlled by default at the organizational level. If so, the organizer will need to adjust this setting for each meeting they create, or alternatively, contact the IT administrator to update the tenant‑level policy to prevent this issue from occurring in the future.

Supported article: IT Admins - Manage lobby options in Microsoft Teams - Microsoft Teams | Microsoft Learn

Please let me know if you have any questions or need further assistance.

Laurence is joining as an anonymous, unverified participant. In Teams, the “Unverified” trust indicator means the person either doesn’t have a Teams account or isn’t signed in with an identity that Teams can verify. For such users, Teams can’t show which organization they come from or confirm who they are.

Because anonymous users can’t be traced or verified, the practical way to stop this recurring guest is to restrict or disable anonymous meeting join for the meetings where this is happening, and/or tighten lobby controls so that only known users can get in.

Actions for the meeting organizer or Teams admin:

1. Control anonymous join at the org level
   • In Teams, anonymous users can join if the “anonymous join” setting is enabled. If this is turned off, only authenticated users (internal, guests, or trusted external organizations) can join.
   • Admins can manage this in the Teams meeting policies as described in “Manage anonymous participant access to Teams meetings” (see reference).
2. Use the lobby to block unverified users
   • Configure the meeting so that only people in the organization and trusted external participants bypass the lobby.
   • Ensure “People who can bypass the lobby” does not include “Everyone.” This forces anonymous/unverified users like Laurence to wait in the lobby, where organizers/presenters can deny them.
3. Prefer verified external participants
   • For external collaborators, use:
     • Guests (B2B guest accounts) – they appear as “(Guest)” and are verifiable.
     • People from trusted organizations – they appear as “(External)” and are verifiable.
   • Avoid relying on anonymous join for recurring or sensitive meetings.
4. If recurring meeting links are widely shared
   • Consider regenerating the meeting link (create a new meeting) and sharing it only with intended participants.

There is no supported way to identify the real-world source of an “Unverified” user beyond what is shown in the meeting UI, because Teams explicitly cannot verify their identity.

References:

• IT Admins - Overview of external collaboration options in Microsoft 365
• Plan for meetings with external participants in Microsoft Teams
• Representation of users outside your organization