Document with esignature issues for external users

Hi @mark Thompson BR,

Microsoft 365 eSignature requires external recipients to authenticate because the document is accessed through a secured SharePoint sharing link. External recipients are provided guest access through Microsoft Entra B2B, which authenticates and manages their guest identities. Therefore, there is no supported option to make the eSignature request anonymous.

However, an external recipient generally does not require a Microsoft 365 or SharePoint license, nor do they necessarily need to create a Microsoft account. If the recipient cannot authenticate using a work, school, Microsoft, or another configured identity provider account, Microsoft Entra B2B can use a one-time passcode sent to the invited email address. Email one-time passcode authentication is enabled by default unless it has been explicitly disabled in the tenant.

A Microsoft-branded sign-in page does not necessarily mean that a Microsoft account is required. The recipient should enter the exact email address to which the signature request was sent so that Microsoft Entra can determine the appropriate authentication method.

If the recipient completes email verification but is then specifically asked for a Microsoft account password, the administrator can check:

• Whether Email one-time passcode authentication has been disabled under Microsoft Entra admin center > External Identities > All identity providers.

• Whether an existing guest object for the recipient is associated with a different email address or identity provider.
• Whether Conditional Access, cross-tenant access, MFA, or Terms of Use policies introduce additional authentication requirements.
• Whether the recipient is using the exact email address to which the invitation was sent.
• Whether the same behavior occurs in an InPrivate or Incognito browser window.

If the existing guest object appears stale or incorrectly linked, the administrator should first review its permissions, group memberships, and access to other shared resources before removing it and sending a new signature request.

If the cause cannot be identified after these checks, or if you need further investigation from Microsoft's technical team, you may want to open a support ticket with Microsoft (administrator access required). A Microsoft support engineer has access to diagnostic tools, tenant-level data, and permissions that are not available to community members, which allows them to review your tenant configuration in greater detail and provide more specific advise or guidance for your eSignature and external access scenario.

Thank you so much for taking time.