Cannot log into MS Teams with my account

Hi @Claudia Roeder, 

Thank you for posting your question in the Microsoft Q&A forum.        

I understand that you’re unable to sign in to Microsoft Teams, and I’d be happy to help you troubleshoot this issue. To better understand your situation and assist you more effectively, could you please help clarify the following:  

1/ Does this issue affect only your account, or are other users in your organization experiencing the same problem?  

2/ Are you experiencing this issue in the Microsoft Teams desktop app, Teams on the web, or both? 

3/ Additionally, please verify that your account has been assigned the correct Microsoft 365 license that includes Microsoft Teams: 

• You can check this yourself by signing in here: My account    
• Alternatively, you can ask your organization’s administrator to confirm your license assignment in the Microsoft 365 Admin Center. 

In the meantime try resetting Microsoft Teams by following these steps:    

1. Go to Settings > Apps > Installed apps, then type Microsoft Teams in the search box.    
2. Locate the New Microsoft Teams app, select the More options button (…) on the right, and choose Advanced options.    
3. In the Reset section, select Reset.    
4. Restart Teams.    

Thank you again for your time and understanding. While my initial response may not resolve the issue immediately, I’d like to gather more details about your situation so I can assist you more effectively.       

I really appreciate your patience, and I’m here to help. Looking forward to your response!       

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Use the status code or error text shown in the bottom-left of the Teams sign-in window or in the error banner to determine the cause and next steps.

1. Check the status code
   • On the Teams sign-in screen, look at the bottom-left corner for a code like 0xCAA20003, 0xCAA90018, etc.
   • If a code is present, match it to the table in the referenced article and follow the specific action. For example:
     • 0xCAA20003 (authorization problem): Ensure the device date and time are correct so secure (HTTPS) connections work.
     • 0xCAA90018 (wrong credentials): The Windows sign-in account is different from the Microsoft 365 account. Sign in again using the correct Microsoft 365 email and password.
     • Network-related codes such as 0xCAA70007, 0xCAA82EE2, 0xCAA82EE7: Confirm internet connectivity and work with the IT admin to ensure firewall/proxy or other apps are not blocking access.
2. If there is no status code or the code is not listed
   • Most sign-in issues are tied to the organization’s Microsoft 365 or domain configuration.
   • Contact the organization’s IT admin or sysadmin, provide the exact error message and any status code, and ask them to check the Microsoft 365/Entra ID configuration and Teams access for the account.
3. If Teams asks to sign in again while already in the app
   • Select the Sign in banner or button in Teams and complete the sign-in, including any multi-factor authentication prompts.
   • If the sign-in window does not appear, quit Teams from the notification area (system tray) and reopen it, then try again.
4. General access checks
   • Confirm the account has the required Microsoft 365 Apps for business or Enterprise license that includes Teams.
   • Make sure any required VPN or corporate network connection is established before opening Teams.

If these steps do not resolve the issue, the IT admin must investigate the tenant/domain configuration or open a support case with Microsoft using the status code and error details.

References:

• How to log in to Microsoft Teams
• Why am I having trouble signing in to Microsoft Teams?
• Restore your access to Microsoft Teams