I work for an MSP which provides technical support for other companies. As such, we have administrative credentials for Microsoft 365 for said companies. Historically, MFA was configured to send a code to our company's main number via SMS. Recently, we changed to a new VOIP system which also accepts SMS messages - with the very annoying exception of SMS authentication messages from Microsoft.
For most of my customers, I was able to alternatively select a phone call as an option and subsequently reconfigure the admin account's MFA for an authenticator application. However I still have two companies where the only option configured was the text code. If I can simply have someone (I need to speak to a person) add our number (the same number) as a secondary authentication option to receive phone call verifications, I can resolve these last two customers. Does anyone have any suggestions on who I can contact or how I can get this issue resolved? My deepest appreciation and thanks in advance.
