사용자가 구독, 계정 설정 및 청구 정보를 관리하는 데 도움이 되는 Microsoft 365 기능입니다.
Hi, bangbangssu
Good day!
Thank you for posting to Microsoft Community. We are glad to assist you!
According to your description, we truly understand how frustrating it is. I'm sorry to hear you're having trouble with the login issue due to changed the phone number.
First of all, before we troubleshoot this issue, would you please allow us to collect some detailed information as below:
- Are you using a Microsoft 365 business account(@xxx.onmicrosoft.com/@yourdomain.com) or a personal account (ending in outlook.com/hotmail.com/live.com/msn.com) or another third-party POP/IMAP account?
Please be kindly to understand that it is really important to us to know your account's type because different accounts are using the different servers.
In case of giving wrong suggestion, we would like to confirm your account's type first and then guide to regain your account's access. Thanks for your understanding in advance!
If you're using an Office 365 for business/education account, it is best for you to contact your organization's administrator to update your new phone number for your account based on the official instructions -Microsoft Entra 다단계 인증을 위한 인증 방법 관리 - Microsoft Entra ID | Microsoft Learn.
Note: Please be kindly to understand that for our community team that we do not have the authority to access into the backend. Thus, please ask your administrator to assist you further for your account's issue.
Thanks for your kindness and your understanding would be highly appreciated.
Hope you all the best.
Sincerely,
Alex | Microsoft Community Moderator.