Cannot sign in to Azure portal with personal Microsoft account — AADSTS16000 (live.com account "does not exist in tenant Microsoft Services") after earlier AADSTS500121 MFA failures

Colin Huisman 0 Reputation points
2026-09-10T20:14:51.7233333+00:00

Hi,

I can no longer sign in to the Azure portal with my personal Microsoft account. My password and the Authenticator approval both succeed, but then it asks for a 6-digit code and this is not accepted. Since then I get error AADSTS16000. I am the sole administrator of the subscription, so nobody else can reset this for me, and I cannot open a support ticket in the portal because I cannot get in. Could you escalate this to the Data Protection or Tenant Recovery team so they can reset my MFA configuration?

Thank you in Advance!

With Kind Regards,

Colin

Microsoft 365 and Office | Subscription, account, billing | For business | Other
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  1. Kai-L 19,050 Reputation points Microsoft External Staff Moderator
    2026-09-10T21:17:58.64+00:00

    Dear Colin,

    Being locked out as the sole administrator is a difficult position, and I understand the urgency. Unfortunately, as a forum moderator, I am not able to escalate this case, reset your MFA, or review your account to fix this directly. My role here is limited to general guidance you can apply from your side.

    The two errors point at different things. AADSTS500121 means the MFA step was not completed successfully. AADSTS16000 is an account selection interrupt, raised when more than one active sign in session exists and Entra cannot determine which identity to use.

    One thing worth asking yourself first: at any point during the number matching prompt, did you select "No, it's not me" or report the request as fraudulent? That action blocks the account and causes every later sign in to fail with 500121, and only an administrator can lift it.

    A few things to try:

    Open an InPrivate window, clear all existing Microsoft sessions first via https://login.microsoftonline.com/logout.srf, then sign in fresh, which addresses the AADSTS16000 interrupt directly. Also note that the 8 digit number shown for Authenticator approval is not the same as a 6 digit verification code. The 6 digit code comes from the account entry inside the Authenticator app itself, so check whether a separate entry exists there for this account.

    On the tenant question, a personal Microsoft account signing in to the portal lands in the Microsoft Services tenant by default, which has no directory associated with it. If the portal loads at all, use Directories + subscriptions to switch to the directory holding your subscription, or go directly to https://portal.azure.com/<your-tenant-ID>.

    If none of that works, ownership verification and recovery sit with Microsoft Support, and you can raise a ticket outside the portal here: Create an Azure support ticket

    I hope this helps. Looking forward to your reply.

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