I cannot log in to my work account using SMS authentication

hi lbalu​ This looks like an issue with SMS-based MFA failing on the service side, not your password — especially since you’re getting through the first step and only failing at verification.

Error 399287 with that message usually points to a problem with the phone-based authentication method (could be carrier routing, number blocking, or a backend issue in Microsoft Entra ID).

A few things you can try:

Click “Sign in another way” and check if you have:

• Authenticator app
• Phone call option
• Alternate method

Try signing in from a different network/device (sometimes helps rule out regional/carrier issues)

Confirm your phone can still:

• Receive other SMS normally
• Isn’t blocking short codes or international messages

Most important step (for work accounts)

Since this is a work account, the quickest fix is to contact your IT admin and ask them to:

Reset your MFA methods

Remove and re-add your phone number

Or enable a different authentication method (like Authenticator)

Admins can do this from Entra ID → Users → Authentication methods.

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