Hi @Alex A
Thank you for posting this in Microsoft Q&A!
I understand that you would like to invite a team member to your azure subscription.
To answer your question, you can invite users with emails from any domain, including third-party company emails, as guest users to your Entra ID.
For more readings, please refer Add a guest user and send an invitation
Hope this helps. Do let us know if you any further queries.
Thank,
Akhilesh.
If this answers your query, do click Accept Answer
and Yes
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