Permission & Access Issues

Fix Cannot Access Vendor SharePoint Site With Microsoft Authenticator

Phi Hung Vo Sep 25, 2026 869 views

Question details

The user is unable to log into an external vendor's SharePoint site because the Microsoft Authenticator app is neither sending push notifications nor accepting manually generated security codes.

How to Fix Cannot Access Vendor SharePoint Site With Microsoft Authenticator

Product: Microsoft SharePoint
Device & OS: not provided
Scenario: Attempting to sign in to a third-party or vendor SharePoint tenant using external guest credentials.
Observed behavior: Microsoft Authenticator fails to send approval notifications, and the generated verification codes are rejected, completely blocking access to the site.

Before you start

Ensure your mobile device has a stable internet connection and that the date and time settings are set to update automatically, as an out-of-sync clock can cause authenticator codes to fail.

Solution 1Recommended

Contact the Vendor's IT Administrator

Because the SharePoint site belongs to an external vendor, their IT team must verify your guest access and authentication policies.

External access issues are usually controlled by the host organization's tenant policies. Even if your Authenticator app works fine for other services, the vendor's specific security rules may be misconfigured or blocking your external guest account.

Record the Error Details

Take a screenshot or accurately write down the exact error code and message you receive when the sign-in fails.

Verify Your Account Type

Make a note of the exact account you are using to sign in, specifically whether it is a personal account or a work/school account.

Reach Out to Vendor Support

Provide the vendor's IT administrator with your error details and ask them to verify your guest access, tenant permissions, and specific multi-factor authentication (MFA) requirements for external users.

Guest Access Requirements: The vendor may need to re-invite you as a guest or reset your MFA session entirely from their Azure Active Directory admin center.

Solution 2

Seek Help in the Microsoft Authenticator Community

If you suspect the issue is strictly related to a malfunction within the Authenticator app itself, the official Microsoft community can provide targeted assistance.

Free Microsoft Office alternative

Looking for a Simpler Way to Collaborate on Documents?

While you wait for the vendor's IT team to resolve your SharePoint authentication issues, you can continue working on your local documents efficiently using WPS Office. It provides a lightweight, hassle-free environment without strict cloud authentication barriers.

1. Download WPS Office: Visit the official WPS website and download the free installation package for your operating system.
2. Install and Launch: Follow the on-screen instructions to install the software, then open it to access Writer, Spreadsheet, and Presentation tools.
3. Open Your Documents: Simply drag and drop your existing Microsoft Office files into WPS Office to continue editing immediately.

Fully compatible with Microsoft Word, Excel, and PowerPoint formats (.docx, .xlsx, .pptx).Work on your documents locally without dealing with complex external tenant access restrictions.Free, lightweight, and easy to install on Windows, Mac, Linux, and mobile devices.Familiar user interface that requires zero learning curve.

Frequently Asked Questions

Why isn't Microsoft Authenticator sending me push notifications?

This can happen if your mobile device has battery optimization enabled for the app, notifications are disabled in your OS settings, or you have an unstable internet connection.

Can I use an alternative MFA method to access the SharePoint site?

You can use an alternative method like an SMS code or email only if the vendor's IT administrator has enabled fallback authentication methods for guest users in their tenant settings.

Why do the generated codes from Microsoft Authenticator fail?

Generated codes are time-sensitive. If the clock on your mobile device is out of sync with the authenticating server by even a few seconds, the codes will be rejected. Always ensure your device time is set to automatic.

What are tenant restrictions in Microsoft SharePoint?

Tenant restriction is a security feature that allows an organization to control which external applications and users can access their resources. If improperly configured, it can unintentionally block legitimate external collaborators.

Document & File Issues