Block external numbers for an organisation as a whole?

Hi Leady7

There is a uservoice to be able to block numbers in the Teams Admin Centre here

https://microsoftteams.uservoice.com/forums/555103-public/suggestions/38028337-block-a-phone-number-in-the-teams-admin-center-for

I would recommend you vote on it to push it up the agenda. Whilst there are few votes I have heard of this ask many times so would recommend. Whilst it's not guaranteed to be picked up the higher this is the more it comes to Microsoft's attention

In addition, there is another uservoice which may provide a workaround

https://microsoftteams.uservoice.com/forums/555103-public/suggestions/34242490-block-specific-phone-numbers

The last comment, on October 30 2019, states

So, the skype for business commandlet actually works to block the number from teams

Set-CsInboundBlockedNumberPattern -Description "SETYOURDESCRIPTION" -Identity <SETIDENTETY> -Pattern "^\+1112223333"

Had originally found the commandlet under teams, but the documentation is blank but the documentation under Skype for Business is still relevant and works under a Teams only organization: https://docs.microsoft.com/en-us/powershell/module/skype/set-csinboundblockednumberpattern?view=skype-ps

I have not tested this personally, but may work for you as an interim measure

Hope that answers your question!

Best, Chris