Microsoft for Startups / Founders Hub portal login loop — sign-in redirects back to signup page (cannot access dashboard or submit support ticket)

The login loop indicates a sign-in/session problem on the Microsoft for Startups Portal side that cannot be fixed from the browser alone. The portal is also the only place to submit a Startups support ticket, so this must be escalated through Microsoft support rather than self-service.

From the available information, the only supported actions are:

1. Try signing in directly to the Microsoft for Startups Portal
   • Go to the Microsoft for Startups Portal sign-in page: https://portal.startups.microsoft.com/login
   • Authenticate with the same Microsoft account that was used for the original Founders Hub/Startups signup.
   • If the loop persists across multiple browsers and private/incognito sessions (as already tested), this confirms the issue is not local cookies/cache.
2. Use the in-portal support flow if access is ever successful
   • Once the portal allows access (even temporarily), use the built-in support flow:
     1. Select the “?” icon in the top-right corner.
     2. Select “Submit a Support Ticket”.
     3. Attach screenshots of the redirect loop and describe that the account appears authenticated but is not being provisioned into a startup profile/dashboard.
3. If profile updates fail once inside the portal
   • If the account can sign in but errors occur when updating profile or startup details:
     1. Sign in to the Microsoft for Startups Portal.
     2. Select the gear icon in the top-right corner.
     3. Use the “My profile” tab to edit name, address, or email, then select “Save changes”.
     4. If errors occur, again use the “?” → “Submit a Support Ticket” path and attach screenshots.
4. If the portal remains completely inaccessible
   • Because the redirect loop prevents reaching the dashboard or the “?” support entry point, resolution requires direct intervention from Microsoft support for the tenant/account behind the scenes. The context only documents the in-portal support path and does not provide an external/manual escalation channel specific to Microsoft for Startups or a way to bind an MSA to a startup profile from outside the portal.
   • In this situation, the next step is to contact Microsoft support through general support channels (for example, via global support phone numbers or standard Microsoft account support) and request that the case be routed to the Microsoft for Startups / Founders Hub team for:
     • Fixing the portal access for the affected Microsoft account, and
     • Verifying or correcting the startup profile association.

Because the redirect loop is on the service side and the only documented Startups-specific support entry point is inside the portal itself, there is no additional self-service remediation or manual verification workflow exposed in the available documentation.

References:

• Microsoft for Startups Portal