New Account is blocked

If the only reason for a new address is the surname change, keeping the existing Microsoft account and adding an alias is usually safer. It preserves OneDrive, purchases, subscriptions, recovery information, and the existing mailbox.

Open the Microsoft account page, go to Your info > Account info > Edit account info, add the new address as an alias, verify it, and then make it the primary alias. Test sign-in and mail delivery with the new address before removing anything. Keep the old alias for a while so messages sent to the previous surname still arrive.

For the blocked account-creation attempt, stop repeated submissions for at least a day and use the official "Account creation has been blocked" support flow. Do not ask another person to create the account or attach their phone number, because that can create a second ownership and recovery problem. If Microsoft continues blocking creation, provide the approximate UTC time and the exact error text to account support; chat agents cannot manually bypass the automated risk decision.