The lobby function in Teams gives some control over who joins a meeting, and when to allow entrance. This capability is convenient to prevent unknown people join your meeting. For known persons, it can be preferred to have ‘an open door’ policy. This can be configured via Teams policies, including for Entra ID B2B guests as known + trusted identities. However, to actual bypass the lobby, does require some ‘trickery’ on the guest side. The trick is to make sure you are indeed in a ‘known’ state in the inviting tenant; as “Unverified” you will still need to wait and enter via the lobby.
Teams Policy to allow B2B guests to bypass lobby
Join meeting in external organizing tenat still routes to lobby
Inspecting the situation from the inviting side gives indication on why the B2B guest is not automatic allowed in: the identity is not 'verified' as known:
2 ways to direct join as Entra ID B2B guest, bypassing lobby
Approach 1 is to explicit self change to the organizing tenant, before joining the meeting:
The 2nd approach is the most simple and seamless, direct join the meeting from the notification popup that the meeting is started in external tenant:
Both approaches result that on moment of joining the Teams Meeting, in the context of organizing tenant the joiner is verified as a known B2B guest, and therefore allowed to direct enter - bypassing the lobby:
