Hello Peter Connolly, here are a couple of steps that you can try.
- Open https://account.microsoft.com/services and sign in using the email addresses that you believe might have been used. Navigate to Services & subscriptions -> Payment & billing -> Order history. You can look for Microsoft 365 Family - Trial and click on Manage and turn off the Recurring billing and cancel the subscription.
- If the subscription exists but you’re logging in with the wrong email, payment methods can expose it. Go to https://account.microsoft.com/billing/payments and log in using the email addresses you believe might have been used. Check saved credit/debit cards, PayPal accounts and check the Order history. If a M365 Family trial exists, it'll show up here.
- Check your mail box (Inbox, Junk, Spam, Deleted) for emails that contain terms such as "Microsoft 365 Family", "Welcome to Microsoft 365", "Thanks for your purchase" from Microsoft (microsoft.com)
If none of these work, it's best to open a support ticket directly with Microsoft and provide some details to verify your identity and they will likely be able to trace the email address based on the payment information.
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