I cancelled 365 because of trouble signing in to my account

Do not delete the account and start over.

For a Microsoft personal account, the supported path is:

1. Use the Sign-in Helper to identify why sign-in with the phone number is being rejected: Sign-in Helper.
2. If the phone number is already tied to another Microsoft account, Microsoft allows a phone number to be associated with only one account at a time.
   • If both accounts are owned by the same person, sign in to the account that currently has the number, remove it there, sign out, then sign in to the target account and add the number.
   • If the number was only recently added to another account, the documented option is to use a different mobile number.
3. If there is no option to add a new phone number under Security > Manage how I sign in, that can be expected. Microsoft notes that adding a new phone number may not be available for some personal accounts. Available methods may instead be recovery email, Microsoft Authenticator, or a passkey.
4. If the goal is to regain access, use the recovery options that match the issue:
   • Forgot password: reset the password.
   • Password stopped working: use the Sign-in Helper.
   • Forgot username: use account lookup.
   • Not receiving codes: use the verification code troubleshooting steps.
5. If the problem is specifically with Outlook mobile, install the latest version of the app because recurring password prompts can happen after security standard updates.
6. If help is still needed, use Contact Microsoft Support. Support agents cannot send password reset links or change account details directly.

Deleting the account is not the recommended fix in the documented guidance.

• I can't sign in to my Microsoft account
• Help with reusing phone numbers in a Microsoft account
• Help with reusing phone numbers in a Microsoft account
• Microsoft account security info & verification codes
• Can't sign in to the Outlook mobile app