i cant log into one of the teams in which im a guest

Hi @Christina Remmo,

Thank you for posting your question to Microsoft Q&A Forum.

I understand you can sign into your regular Microsoft Teams account, but you cannot access the guest organization you were invited to. When you try to sign in, Microsoft Authenticator does not provide a verification code and you receive messages indicating the account does not exist, even though you are using the same email address.

Guest access in Microsoft Teams is managed inside the host organization’s Microsoft Entra ID directory. Although you use the same email, your guest identity is separate from your home account. If multi‑factor authentication for the host tenant is not set up for your guest identity, or if the sign‑in is using cached credentials from your home tenant, you may see “account doesn’t exist” errors or you may not receive verification prompts.

You can take the following steps to address the issue:

1. Sign out of all Teams sessions
   • On desktop: Click your profile picture → Sign out. Close the app completely.
   • On web: Sign out at teams.microsoft.com, then close the browser.
2. Accept or re‑accept the guest invitation
   • Locate the original invitation email from the host organization and click Accept.
   • If you can’t find it, ask the host admin to resend the guest invitation. (This refreshes your guest account in their tenant.

If it still doesn’t work, you should reach out to the host admin.

The host admin should:

• Confirm your guest user exists and is Enabled in Microsoft Entra ID.
• Remove and re‑invite your guest user, or reset MFA for the guest.
• Check Conditional Access policies that might block guest sign‑in (e.g., device compliance required).

Note: Your regular Teams account and your guest Teams account are managed by two separate tenants. Make sure you contact the correct person, either the admin or owner in the guest tenant, who is responsible for inviting and managing your guest access.

Quick tips

• Using Incognito/Private mode is the fastest way to rule out cached sign‑in conflicts.
• If you have multiple Microsoft accounts on the device, choose “Sign in with another account” during login and explicitly select the guest organization when prompted.
• The Authenticator app can hold multiple work/school identities, make sure the one for the host org appears and is verified.

I hope this provides enough clarity and helps you stay inform with your current situation.

Thank you for your patience and your understanding. If you have any questions or need further assistance, please feel free to share them in the comments on this post so I can continue to support you.    

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If you're having trouble logging into a Microsoft Teams guest account, here are some steps you can take to troubleshoot the issue:

1. Check Your Email: Ensure that you have received a welcome email from the team owner. This email contains important information about accessing the team.
2. Use a Private or Incognito Browser Window: Sometimes, browser cache issues can cause login problems. Try accessing Teams from a private or incognito window and enter your credentials there.
3. One-Time Passcode Authentication: If you are using a personal email and not a work or school account, you may need to use a one-time passcode to authenticate. Make sure you check your email for this code if prompted.
4. Account Conflicts: If your email is associated with both a work and personal account, this may cause conflicts. You might need to unlink these accounts to create a free Teams account or use the correct credentials for your work account.
5. Check Guest Access Settings: Ensure that guest access is properly configured for the team you are trying to join. Team owners can add guests, but it may take up to 12 hours for access to be granted after being added.
6. Contact Support: If none of these steps resolve the issue, consider reaching out to your IT department or Microsoft support for further assistance.

These steps should help you troubleshoot the login issue you're experiencing with your guest account in Microsoft Teams.

References:

• Guest access in Microsoft Teams
• "Someone has already set up Teams for your organization" error in Microsoft Teams