My personal account is currently connected with a random corporate account which prevents me from registering a New App on Azure

The behavior is caused by the personal Microsoft account being associated with a work/school (Microsoft Entra ID) tenant that shares the same email address or domain, which then affects sign-in and app registration.

To move forward as an independent developer, there are two supported directions based on the documented patterns:

1. Rename the personal Microsoft account so it no longer conflicts with a work/school identity
   When a personal Microsoft account and a work/school account share the same email, Microsoft sign-in and resource access (including app registration) can be impacted. The recommended fix is to rename the personal account to use a different email address (alias) that is not tied to any organization:
   • Go to the Manage how you sign in section of the Microsoft account.
   • Add a new email address (alias) or use an existing one that is not part of any organization.
   • Set that alias as Make primary.
   This effectively separates the personal Microsoft account from the work/school identity that shares the same address and avoids the “which account do you want to use” and similar conflicts during sign-in and app registration. Notes from the documentation:
   • An alias is a nickname for the account that shares the same inbox and settings. Any alias can be used to sign in, with the same password.
   • The primary alias is what appears on devices and services (Windows, Xbox, etc.).
   • Renaming may not be desirable if Xbox Developer, Visual Studio, or MSDN subscriptions are tied to the current sign-in address; in that case, consider carefully before changing the primary alias.
2. If the issue is specifically with an Entra tenant connection (for example, Azure DevOps or similar)
   Where a personal Microsoft account is conflicting with a work account in a tenant, the guidance is to rename the personal Microsoft account to a different email address that does not conflict with the work email. This avoids being prompted to choose between accounts and prevents the wrong identity from being used when accessing Azure resources or registering apps.

If the tenant itself is unknown and cannot be managed directly, renaming the personal Microsoft account to a unique, non-organizational alias is the documented, user-controllable way to break the conflict and proceed with independent app registration under the personal identity.

References:

• Which account do you want to use?
• Change your organization connection to a different Microsoft Entra ID