A family of Microsoft word processing software products for creating web, email, and print documents.
Hello
If the account is not yours, and you don't have the credential to sign in, I would be completely honest with you, it would be very challenging to cancel it via Microsoft, because Microsoft takes account security very seriously. If it can just go by what you said, our accounts can be easily manipulated by others.
You have two options here:
- Follow the legal process to claim ownership of his account. https://support.microsoft.com/en-us/account-billing/accessing-outlook-com-onedrive-and-other-microsoft-services-when-someone-has-died-ebbd2860-917e-4b39-9913-212362da6b2f
- Just cancel it from his credit card issuer, or bank. This might be an easier route as you don't have to deal with Microsoft account ownership takeover.