The access to customer's Sharepoint doesn't work even though the customer hasn't changed it

Dear @Pauliina Inervo,
Thank you for posting your question in the Microsoft Q&A forum. I understand you can’t open your customer’s SharePoint anymore. It worked before, and this started after account/alias changes. Your Authenticator also doesn’t show the right account. I’m here to help.

To better assistance, could you please confirm following information:

1. When you open the SharePoint link, do you see “Pick an account”? Which account shows first?
2. Can you sign in at https://www.office.com using [your_work_account@domain]? What happens?
3. In Windows > Settings > Accounts > Access work or school, do you still see [your_work_account@domain]?
4. In Microsoft Authenticator, is there an entry for [your_work_account@domain]?
5. What exact message appears on the SharePoint link (Access Denied, sign-in loop, MFA prompt, etc.)?
6. Has your customer confirmed that your access for [your_work_account@domain] is still active?

In the meantime, please try:

Step 1: Sign out of all Microsoft accounts in Office apps and at office.com; clear browser cookies for Microsoft/Office.

• On Office apps (Word, Excel, Outlook, Teams, etc.)
• Open any Office app (Word, Excel…).
• Go to File > Account.
• If you see multiple accounts listed, click Sign out for all of them.
• Close all Office apps completely.

On Windows

• Go to Settings > Accounts > Email & Accounts.
• Under Accounts used by other apps, remove any personal Microsoft accounts you do not want.
• Go to Settings > Accounts > Access work or school > click any account you don’t need > Disconnect.

On browsers (Edge/Chrome)

• Open your browser > click your profile picture.
• Sign out of any Microsoft account shown there.
• Go to https://office.com > Sign out (top right).
• Clear cached sign-ins: Settings > Privacy, Search and Service/ Privacy and Security. > Clear browsing data > choose "Cookies & other site data".

Step 2: Remove from Credential Manager

• Press Windows key > type Credential Manager > open it.
• Select Windows Credentials.
• In the list, remove any entries containing: trimmi-inspire.com, outlook.com, onmicrosoft.com, Office / SharePoint / MicrosoftOfficeHub credential
• Restart your computer again.

Step 3: Sign back in only with [your_work_account@domain] in Office and at office.com.

• Go to https://office.com.
• Click Sign in.
• Enter: [your_work_account@domain]
• Enter the password for this account.
• Open an Office app and make sure the same account is shown under File > Account.

Step 4: Ask your customer’s admin to reset MFA for [your_work_account@domain], then re-add it in Microsoft Authenticator.

Step 5: Reopen the SharePoint link and choose “Work or school account” (not the personal account).

• Click the SharePoint link again.
• When a popup appears asking which account to use: Select Work or school account
• DO NOT select the personal Outlook account
• If asked to authenticate, complete MFA with the newly added Authenticator entry.
• You should now regain access if the correct identity is used

Please understand that our initial response does not always resolve the issue immediately. However, with your help and more detailed information, we can work together to find a solution.

I truly appreciate your patience and understanding. If you have any further questions or need further clarification, please feel free to reach out. I'm looking forward to hearing from you. 

Thank you for your cooperation.

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It seems that the issue you are experiencing with accessing your customer's SharePoint may be related to the changes you made to your account and the alias you added. Here are a few steps you can take to troubleshoot the problem:

1. Check Permissions: Ensure that you still have the appropriate permissions to access the SharePoint site. If your account has changed, you may need to have the permissions re-granted.
2. Account Confusion: Since you mentioned that you have both a business account and an alias, make sure you are using the correct account when trying to access SharePoint. If the alias is not recognized as a business account, it might be causing the access issues.
3. Authenticator Issues: The Microsoft Authenticator app may not recognize the new alias as a business account. Try to log in using the original business account email (******@trimmi-inspire.com) and ensure that you have access to the correct authentication method linked to that account.
4. Access Denied Errors: If you are receiving access denied errors, it could be due to the account being different from the one that was originally granted access. You may need to contact the SharePoint administrator to verify your access.
5. Revisit Account Settings: If you have recently made changes to your Microsoft account settings, revisit those settings to ensure everything is configured correctly.

If after these steps you are still unable to access SharePoint, consider reaching out to Microsoft technical support for further assistance.

References:

• Unable to access SharePoint Online
• Access Denied or You need permission errors in SharePoint Online and OneDrive