How to find out the email account I setup perviously?

Dear @Vivian Zhou,

I understand how concerning it can be to see recurring charges related to a business account when you're unsure whether one was previously created.

Based on your description, it’s very likely that a Microsoft 365 Business (Work or School) account was set up in the past using your personal email address as the billing contact.

When a Microsoft 365 Business subscription is created, the system typically generates a separate admin account (for example, something ending ******@yourcompany.onmicrosoft.com). This admin account is what’s actually tied to the subscription and billing, even though billing notifications may still be sent to your personal email address.

If you’re unable to sign in to the original admin account, the recommended next step is to contact Microsoft Support so they can verify your identity and help you regain access. Therefore, I would recommend you create a Microsoft 365 trial tenant to contact the support team online. 

Step 1: Sign up for a new Microsoft 365 Business trial using this link: Compare All Microsoft 365 Plans. You will need to use a different, personal email address to register. 

Step 2: Once the trial account is created, log in to its Admin Center > From the Admin Center, open a new Service Request. For reference:  Get support | Microsoft Docs   

Step 3: In the ticket description, explain that you card is charged and that you need to speak with the Data Protection team to verify your identity and regain access to the administrator account. Provide your good contact number for them to reach you. 

Please be prepared to provide supporting information such as: Business name (if applicable), billing or invoice details, payment method used, any known tenant or domain name.

Important: Please remember to cancel the trial subscription after your original account issue is resolved to avoid any future charges. 

Note: Please understand that as a forum moderator, my role is to provide general guidance and troubleshooting support. I don’t have access to internal systems or backend tools, and I appreciate your understanding of these limits.

I hope the information shared helps point you in the right direction. Please try the steps above and let me know if they work. If not, we can continue working together to narrow this down.

The first response may not always resolve the issue right away, but with your help and more details, we can work toward a solution.

Thank you for your patience and understanding. I'm looking forward for your reply.

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To regain access and understand what the business charge is for, follow these steps:

1. Check which email is a Microsoft account
   • Go to the Microsoft account sign-in page: https://account.microsoft.com
   • Enter the personal email address that receives the monthly bill.
   • If a password prompt appears, that email is a Microsoft account.
   • If the message says “We couldn't find an account with that username” or “That Microsoft account doesn't exist,” then that email is not a Microsoft account. In that case:
     • Check for spelling mistakes in the email address (for example, name variants or .com vs .co.uk).
     • The account may have been closed; see the guidance in the referenced article about closed accounts.
2. Sign in and review subscriptions and billing
   • After confirming the email is a Microsoft account, sign in at https://account.microsoft.com with that email and its password.
   • Use the Services & subscriptions and Payment & billing areas (via the Microsoft account dashboard) to see:
     • Active Microsoft 365 or other subscriptions.
     • What product or service is being billed monthly.
3. If it is an Office 365/Microsoft 365 business subscription
   • Sign in to Office 365 with admin credentials for that account: Sign into Office 365.
   • Select the app launcher (top left) → Admin.
   • Go to Billing → Subscriptions to see all business subscriptions and their status.
4. Investigate the specific charge
   • If the charge still is not clear, go to the Manage your payments page of the Microsoft account dashboard and select Investigate next to the unrecognized charge, as described in the billing investigation article. This helps identify whether it is a subscription, in-app purchase, pre-order, or another type of charge.
5. If the email used for billing is not a Microsoft account
   • If the personal email that receives the bill is not recognized as a Microsoft account, check other email addresses that might have been used when setting up the business subscription (work email, alternate personal email, etc.) using the same sign-in test.
6. If access is still not possible
   • If none of the emails work or the account appears closed, use the Sign-in Helper tool linked from the “How to check if your email address is a Microsoft account” article to recover the correct username or resolve sign-in issues.

These steps allow identifying which email is tied to the business subscription and then viewing or managing the subscription and its charges.

References:

• How to check if your email address is a Microsoft account
• View your Office 365 business subscription
• How to investigate a billing charge from Microsoft
• Check products or services where you used your Microsoft account