Forgot phone number and cant sign into xbox now

For a personal Microsoft/Xbox account, if the code is going to an old phone number and there is no access to any current verification method, the supported path is:

1. Start signing in to the Microsoft account.
2. At Verify your identity, select I don't have any of these.
3. Follow the prompts to replace the security info with a new method.
4. After replacing all security info, there is a 30-day wait before sign-in is available again.

If the password is known and there is still access to at least one existing security method, use Advanced security options to add a new way to sign in or verify, confirm it with the code sent there, and then remove the old phone number.

Important:

• Do not keep making repeated code requests. That can temporarily block code delivery.
• Support agents cannot send verification codes or change account details for account recovery.
• If normal recovery is not working, use the Sign-in helper.

If the password is also forgotten and there is no access to any security info, use the account recovery form.

References:

• Troubleshoot Microsoft verification code issues
• I can't sign in to my Microsoft account