Account not verified, when trying SMS or Call MFA

Question

Account not verified, when trying SMS or Call MFA

jasper goris 0

Hi,

We're a IT Company which managed +/- 400 Office 365 Tenants.

Recently we're running into the issue that the MFA option for SMS and Calls is not working for some tenants.

We're getting the Error: Account not verified.

We're expierincing this on multiple Office 365 Tenant. New tenants aswell as older tentants.

All MFA numbers setup are Belgian numbers. (+32)

We now using de Authenticator app won't give this error. But in some cases we won't to use the SMS or Call function as MFA.

Because we're expiencing this issue across multiple tenants, even brand new ones.

I Would think it's a general microsoft issue.

We've already tried making a support case at microsoft, but with no effect.

Thanks in advance for the help!

Kind Regards
Jasper

Shubham Sharma 17,930 Reputation points Microsoft External Staff Moderator

2026-01-02T15:23:23.3766667+00:00

Hello jasper goris

Thank you for reaching out to Microsoft Q&A.

I understand that you are running into the issue that the MFA option for SMS and Calls is not working for some tenants.

Could you please provide the error screenshot so that we’ll be able to analyze the issue and guide you accordingly.
jasper goris 0 Reputation points

2026-01-02T15:34:04.1366667+00:00

Hi,

Here you can see an example of the error
Shubham Sharma 17,930 Reputation points Microsoft External Staff Moderator

2026-01-02T17:27:48.7033333+00:00
Hello jasper goris

To proceed, I will need a few details from you. As this information contains Personally Identifiable Information (PII), please share the following details via private message only:

Contact phone number (add +Country code)

Contact email address

Global admin email address (affected account)

Tenant Name

Country

Country code

Time Zone

Tenant id/ Domain Name

Subscription id

Please send me the detail via private message. So, we can assist you further.
Shubham Sharma 17,930 Reputation points Microsoft External Staff Moderator

2026-01-06T06:48:55.2066667+00:00

Hello jasper goris

Could you please provide an update on the post?
Shubham Sharma 17,930 Reputation points Microsoft External Staff Moderator

2026-01-20T02:31:59.76+00:00

Hello jasper goris

Thank you for sharing your details via private message.

I’ve reached out to the engineering team regarding the MFA issue on your account. They have now unblocked it from the backend and cleared the bad reputation associated with it. You should be able to log in to the Azure Portal without any issues.

Please try signing in and verify if you can complete SMS authentication successfully. Let me know if you encounter any problems.

As a best practice, I recommend registering the Microsoft Authenticator method for your account instead of relying on SMS. SMS and voice call authentication methods are more vulnerable to IRSF attacks (telephony fraud) and are generally less secure.

For better practice, I recommend registering with Microsoft Authenticator method to your account instead of SMS method as these SMS/Voice telecom auth methods are susceptible to IRSF attacks telephony fraud.

If the query has been resolved, please take a moment to accept the answer and upvote it 👍 to make it helpful to the community.

Thank you for helping to improve Microsoft Q&A!

Your answer

Shubham Sharma 17,930 Reputation points Microsoft External Staff Moderator

2026-01-02T15:23:23.3766667+00:00

Hello jasper goris

Thank you for reaching out to Microsoft Q&A.

I understand that you are running into the issue that the MFA option for SMS and Calls is not working for some tenants.

Could you please provide the error screenshot so that we’ll be able to analyze the issue and guide you accordingly.
jasper goris 0 Reputation points

2026-01-02T15:34:04.1366667+00:00

Hi,

Here you can see an example of the error
Shubham Sharma 17,930 Reputation points Microsoft External Staff Moderator

2026-01-02T17:27:48.7033333+00:00

Hello jasper goris

To proceed, I will need a few details from you. As this information contains Personally Identifiable Information (PII), please share the following details via private message only:

Contact phone number (add +Country code)

Contact email address

Global admin email address (affected account)

Tenant Name

Country

Country code

Time Zone

Tenant id/ Domain Name

Subscription id

Please send me the detail via private message. So, we can assist you further.
Shubham Sharma 17,930 Reputation points Microsoft External Staff Moderator

2026-01-06T06:48:55.2066667+00:00

Hello jasper goris

Could you please provide an update on the post?
Shubham Sharma 17,930 Reputation points Microsoft External Staff Moderator

2026-01-20T02:31:59.76+00:00

Hello jasper goris

Thank you for sharing your details via private message.

I’ve reached out to the engineering team regarding the MFA issue on your account. They have now unblocked it from the backend and cleared the bad reputation associated with it. You should be able to log in to the Azure Portal without any issues.

Please try signing in and verify if you can complete SMS authentication successfully. Let me know if you encounter any problems.

As a best practice, I recommend registering the Microsoft Authenticator method for your account instead of relying on SMS. SMS and voice call authentication methods are more vulnerable to IRSF attacks (telephony fraud) and are generally less secure.

For better practice, I recommend registering with Microsoft Authenticator method to your account instead of SMS method as these SMS/Voice telecom auth methods are susceptible to IRSF attacks telephony fraud.

If the query has been resolved, please take a moment to accept the answer and upvote it 👍 to make it helpful to the community.

Thank you for helping to improve Microsoft Q&A!